kstd: move string tests

3 files changed, 1907 insertions, 2063 deletions

diff --git a/libs/kstd/CMakeLists.txt b/libs/kstd/CMakeLists.txt
index d85f003..5a95757 100644
--- a/libs/kstd/CMakeLists.txt
+++ b/libs/kstd/CMakeLists.txt
@@ -77,7 +77,6 @@ if(BUILD_TESTING)
         "kstd/flat_map.test.cpp"
         "kstd/format.test.cpp"
         "kstd/vector.test.cpp"
-        "kstd/bits/basic_string.test.cpp"
         "kstd/bits/observer_ptr.test.cpp"
         "kstd/test_support/os_panic.test.cpp"
         "kstd/string.test.cpp"
diff --git a/libs/kstd/kstd/bits/basic_string.test.cpp b/libs/kstd/kstd/bits/basic_string.test.cpp
deleted file mode 100644
index 8f3a00d..0000000
--- a/libs/kstd/kstd/bits/basic_string.test.cpp
+++ /dev/null
@@ -1,1962 +0,0 @@
-#include <kstd/bits/basic_string.hpp>
-
-#include <kstd/allocator>
-#include <kstd/test_support/os_panic.hpp>
-
-#include <catch2/catch_test_macros.hpp>
-
-#include <cstring>
-#include <forward_list>
-#include <initializer_list>
-#include <iterator>
-#include <memory>
-#include <sstream>
-#include <string_view>
-#include <type_traits>
-#include <utility>
-
-using char_string = kstd::basic_string<char>;
-
-SCENARIO("Basic string of char initialization and construction", "[string]")
-{
-  THEN("All type aliases are present")
-  {
-    REQUIRE(std::is_same_v<char_string::traits_type, kstd::char_traits<char>>);
-    REQUIRE(std::is_same_v<char_string::value_type, char>);
-    REQUIRE(std::is_same_v<char_string::allocator_type, kstd::allocator<char>>);
-    REQUIRE(std::is_same_v<char_string::size_type, std::allocator_traits<kstd::allocator<char>>::size_type>);
-    REQUIRE(
-        std::is_same_v<char_string::difference_type, std::allocator_traits<kstd::allocator<char>>::difference_type>);
-    REQUIRE(std::is_same_v<char_string::reference, char &>);
-    REQUIRE(std::is_same_v<char_string::const_reference, char const &>);
-    REQUIRE(std::is_same_v<char_string::pointer, std::allocator_traits<kstd::allocator<char>>::pointer>);
-    REQUIRE(std::is_same_v<char_string::const_pointer, std::allocator_traits<kstd::allocator<char>>::const_pointer>);
-    REQUIRE(std::is_same_v<char_string::iterator, char *>);
-    REQUIRE(std::is_same_v<char_string::const_iterator, char const *>);
-    REQUIRE(std::is_same_v<char_string::reverse_iterator, std::reverse_iterator<char *>>);
-    REQUIRE(std::is_same_v<char_string::const_reverse_iterator, std::reverse_iterator<char const *>>);
-  }
-
-  THEN("npos is present")
-  {
-    REQUIRE(char_string::npos == char_string::size_type(-1));
-  }
-
-  GIVEN("An empty context")
-  {
-    WHEN("constructing by default")
-    {
-      auto s = char_string{};
-
-      THEN("the string is empty")
-      {
-        REQUIRE(s.empty());
-      }
-
-      THEN("the size is equal to zero")
-      {
-        REQUIRE(s.size() == 0);
-      }
-
-      THEN("the length is equal to zero")
-      {
-        REQUIRE(s.length() == 0);
-      }
-
-      THEN("at raises a panic")
-      {
-        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
-      }
-
-      THEN("data returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.data() == '\0');
-      }
-
-      THEN("c_str returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.c_str() == '\0');
-      }
-
-      THEN("the string is convertible to an empty string view")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.empty());
-      }
-    }
-
-    WHEN("constructing with 10 copies of the letter 'a'")
-    {
-      auto s = char_string{10, 'a'};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 10")
-      {
-        REQUIRE(s.size() == 10);
-      }
-
-      THEN("the length is equal to 10")
-      {
-        REQUIRE(s.length() == 10);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns a")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'a');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns a")
-      {
-        REQUIRE(s[s.size() - 1] == 'a');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns a")
-      {
-        REQUIRE(s.back() == 'a');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 10")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 10);
-      }
-
-      THEN("the string converts to a string view of length 10")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 10);
-      }
-    }
-
-    WHEN("constructing with 20 copies of the letter 'a'")
-    {
-      auto s = char_string{20, 'a'};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns a")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'a');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns a")
-      {
-        REQUIRE(s[s.size() - 1] == 'a');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns a")
-      {
-        REQUIRE(s.back() == 'a');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing with an input iterator pair of 10 characters")
-    {
-      auto source = std::istringstream{"abcdefghij"};
-      auto s = char_string{std::istream_iterator<char>{source}, std::istream_iterator<char>{}};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 10")
-      {
-        REQUIRE(s.size() == 10);
-      }
-
-      THEN("the length is equal to 10")
-      {
-        REQUIRE(s.length() == 10);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns j")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'j');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns j")
-      {
-        REQUIRE(s[s.size() - 1] == 'j');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns j")
-      {
-        REQUIRE(s.back() == 'j');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 10")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 10);
-      }
-
-      THEN("the string converts to a string view of length 10")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 10);
-      }
-    }
-
-    WHEN("constructing with an input iterator pair of 20 characters")
-    {
-      auto source = std::istringstream{"abcdefghijABCDEFGHIJ"};
-      auto s = char_string{std::istream_iterator<char>{source}, std::istream_iterator<char>{}};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is greater than or equal to 20")
-      {
-        REQUIRE(s.capacity() >= 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing with a forward iterator pair of 10 characters")
-    {
-      auto source = std::forward_list{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'};
-      auto s = char_string{source.cbegin(), source.cend()};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 10")
-      {
-        REQUIRE(s.size() == 10);
-      }
-
-      THEN("the length is equal to 10")
-      {
-        REQUIRE(s.length() == 10);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns j")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'j');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns j")
-      {
-        REQUIRE(s[s.size() - 1] == 'j');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns j")
-      {
-        REQUIRE(s.back() == 'j');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 10")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 10);
-      }
-
-      THEN("the string converts to a string view of length 10")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 10);
-      }
-    }
-
-    WHEN("constructing with a forward iterator pair of 20 characters")
-    {
-      auto source = std::forward_list{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
-                                      'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
-      auto s = char_string{source.cbegin(), source.cend()};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing from a null pointer with zero size")
-    {
-      auto s = char_string{static_cast<char const *>(nullptr), 0};
-
-      THEN("the string is empty")
-      {
-        REQUIRE(s.empty());
-      }
-
-      THEN("the size is equal to 0")
-      {
-        REQUIRE(s.size() == 0);
-      }
-
-      THEN("the length is equal to 0")
-      {
-        REQUIRE(s.length() == 0);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at raises a panic")
-      {
-        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
-      }
-
-      THEN("data returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.data() == '\0');
-      }
-
-      THEN("c_str returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.c_str() == '\0');
-      }
-
-      THEN("the string is convertible to an empty string view")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.empty());
-      }
-    }
-
-    WHEN("constructing from a from a null pointer and non-zero size")
-    {
-      THEN("a panic is raised")
-      {
-        REQUIRE_THROWS_AS((char_string{static_cast<char const *>(nullptr), 1}), kstd::tests::os_panic);
-      }
-    }
-
-    WHEN("constructing from a non-null pointer and zero size")
-    {
-      auto ptr = "abcd";
-      auto s = char_string{ptr, 0};
-
-      THEN("the string is empty")
-      {
-        REQUIRE(s.empty());
-      }
-
-      THEN("the size is equal to 0")
-      {
-        REQUIRE(s.size() == 0);
-      }
-
-      THEN("the length is equal to 0")
-      {
-        REQUIRE(s.length() == 0);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at raises a panic")
-      {
-        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
-      }
-
-      THEN("data returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.data() == '\0');
-      }
-
-      THEN("c_str returns a pointer poiting to a null byte")
-      {
-        REQUIRE(*s.c_str() == '\0');
-      }
-
-      THEN("the string is convertible to an empty string view")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.empty());
-      }
-    }
-
-    WHEN("constructing from a non-null pointer and a size of 4")
-    {
-      auto ptr = "abcd";
-      auto s = char_string{ptr, 4};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 4")
-      {
-        REQUIRE(s.size() == 4);
-      }
-
-      THEN("the length is equal to 4")
-      {
-        REQUIRE(s.length() == 4);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns d")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'd');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns d")
-      {
-        REQUIRE(s[s.size() - 1] == 'd');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns d")
-      {
-        REQUIRE(s.back() == 'd');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 4")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 4);
-      }
-
-      THEN("the string converts to a string view of length 4")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 4);
-      }
-    }
-
-    WHEN("constructing from a non-null pointer and a size of 20")
-    {
-      auto ptr = "abcdefghijABCDEFGHIJ";
-      auto s = char_string{ptr, 20};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing from a C-style string of length 4")
-    {
-      auto ptr = "abcd";
-      auto s = char_string{ptr};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 4")
-      {
-        REQUIRE(s.size() == 4);
-      }
-
-      THEN("the length is equal to 4")
-      {
-        REQUIRE(s.length() == 4);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns d")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'd');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns d")
-      {
-        REQUIRE(s[s.size() - 1] == 'd');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns d")
-      {
-        REQUIRE(s.back() == 'd');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 4")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 4);
-      }
-
-      THEN("the string converts to a string view of length 4")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 4);
-      }
-    }
-
-    WHEN("constructing from a C-style string of length 20")
-    {
-      auto ptr = "abcdefghijABCDEFGHIJ";
-      auto s = char_string{ptr};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing from a string view of length 4")
-    {
-      using namespace std::string_view_literals;
-
-      auto view = "abcd"sv;
-      auto s = char_string{view};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 4")
-      {
-        REQUIRE(s.size() == 4);
-      }
-
-      THEN("the length is equal to 4")
-      {
-        REQUIRE(s.length() == 4);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns d")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'd');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns d")
-      {
-        REQUIRE(s[s.size() - 1] == 'd');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns d")
-      {
-        REQUIRE(s.back() == 'd');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 4")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 4);
-      }
-
-      THEN("the string converts to a string view of length 4")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 4);
-      }
-    }
-
-    WHEN("constructing from a string view of length 20")
-    {
-      using namespace std::string_view_literals;
-
-      auto view = "abcdefghijABCDEFGHIJ"sv;
-      auto s = char_string{view};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-
-      THEN("the capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("at(0) returns a")
-      {
-        REQUIRE(s.at(0) == 'a');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns a")
-      {
-        REQUIRE(s[0] == 'a');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.data() == 'a');
-      }
-
-      THEN("c_str returns a pointer pointing to an a")
-      {
-        REQUIRE(*s.c_str() == 'a');
-      }
-
-      THEN("c_str points to the start of a c-string of length 20")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 20);
-      }
-
-      THEN("the string converts to a string view of length 20")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 20);
-      }
-    }
-
-    WHEN("constructing from a substring of a string view of length 4")
-    {
-      using namespace std::string_view_literals;
-
-      auto view = "abcd"sv;
-      auto s = char_string{view, 1, 4};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 3")
-      {
-        REQUIRE(s.size() == 3);
-      }
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-
-      THEN("the capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("at(0) returns b")
-      {
-        REQUIRE(s.at(0) == 'b');
-      }
-
-      THEN("at(size() - 1) returns d")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'd');
-      }
-
-      THEN("[0] returns b")
-      {
-        REQUIRE(s[0] == 'b');
-      }
-
-      THEN("[size() - 1] returns d")
-      {
-        REQUIRE(s[s.size() - 1] == 'd');
-      }
-
-      THEN("front returns b")
-      {
-        REQUIRE(s.front() == 'b');
-      }
-
-      THEN("back returns d")
-      {
-        REQUIRE(s.back() == 'd');
-      }
-
-      THEN("data returns a pointer pointing to an b")
-      {
-        REQUIRE(*s.data() == 'b');
-      }
-
-      THEN("c_str returns a pointer pointing to an b")
-      {
-        REQUIRE(*s.c_str() == 'b');
-      }
-
-      THEN("c_str points to the start of a c-string of length 3")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 3);
-      }
-
-      THEN("the string converts to a string view of length 3")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 3);
-      }
-    }
-
-    WHEN("constructing from a substring of a string view of length 20")
-    {
-      using namespace std::string_view_literals;
-
-      auto view = "abcdefghijABCDEFGHIJ"sv;
-      auto s = char_string{view, 1, 20};
-
-      THEN("the string is not empty")
-      {
-        REQUIRE_FALSE(s.empty());
-      }
-
-      THEN("the size is equal to 19")
-      {
-        REQUIRE(s.size() == 19);
-      }
-
-      THEN("the length is equal to 19")
-      {
-        REQUIRE(s.length() == 19);
-      }
-
-      THEN("the capacity is equal to 19")
-      {
-        REQUIRE(s.capacity() == 19);
-      }
-
-      THEN("at(0) returns b")
-      {
-        REQUIRE(s.at(0) == 'b');
-      }
-
-      THEN("at(size() - 1) returns J")
-      {
-        REQUIRE(s.at(s.size() - 1) == 'J');
-      }
-
-      THEN("[0] returns b")
-      {
-        REQUIRE(s[0] == 'b');
-      }
-
-      THEN("[size() - 1] returns J")
-      {
-        REQUIRE(s[s.size() - 1] == 'J');
-      }
-
-      THEN("front returns b")
-      {
-        REQUIRE(s.front() == 'b');
-      }
-
-      THEN("back returns J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("data returns a pointer pointing to an b")
-      {
-        REQUIRE(*s.data() == 'b');
-      }
-
-      THEN("c_str returns a pointer pointing to an b")
-      {
-        REQUIRE(*s.c_str() == 'b');
-      }
-
-      THEN("c_str points to the start of a c-string of length 19")
-      {
-        REQUIRE(std::strlen(s.c_str()) == 19);
-      }
-
-      THEN("the string converts to a string view of length 19")
-      {
-        auto view = static_cast<std::string_view>(s);
-        REQUIRE(view.length() == 19);
-      }
-    }
-  }
-
-  GIVEN("An existing short string, of length 10")
-  {
-    auto other = char_string{"abcdefghij"};
-
-    WHEN("constructing by copy")
-    {
-      auto s = other;
-
-      THEN("the sizes are identical")
-      {
-        REQUIRE(s.size() == other.size());
-      }
-
-      THEN("the capacities are idendtical")
-      {
-        REQUIRE(s.capacity() == other.capacity());
-      }
-
-      THEN("the underlying strings are identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s.data(), other.data()));
-      }
-    }
-
-    WHEN("constructing by move")
-    {
-      auto s = std::move(other);
-
-      THEN("size is equal to 10")
-      {
-        REQUIRE(s.size() == 10);
-      }
-
-      THEN("capacity is equal to 15")
-      {
-        REQUIRE(s.capacity() == 15);
-      }
-
-      THEN("front() return an a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back() return a j")
-      {
-        REQUIRE(s.back() == 'j');
-      }
-
-      THEN("The moved from object's size is 0")
-      {
-        REQUIRE(other.size() == 0);
-      }
-
-      THEN("The moved from object's capacity is 15")
-      {
-        REQUIRE(other.capacity() == 15);
-      }
-
-      THEN("c_str() on the moved from object points to a null byte")
-      {
-        REQUIRE(*other.c_str() == '\0');
-      }
-    }
-  }
-
-  GIVEN("An existing short string, of length 20")
-  {
-    auto other = char_string{"abcdefghijABCDEFGHIJ"};
-
-    WHEN("constructing by copy")
-    {
-      auto s = other;
-
-      THEN("the sizes are identical")
-      {
-        REQUIRE(s.size() == other.size());
-      }
-
-      THEN("the capacities are idendtical")
-      {
-        REQUIRE(s.capacity() == other.capacity());
-      }
-
-      THEN("the underlying strings are identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s.data(), other.data()));
-      }
-    }
-
-    WHEN("constructing by move")
-    {
-      auto s = std::move(other);
-
-      THEN("size is equal to 20")
-      {
-        REQUIRE(s.size() == 20);
-      }
-
-      THEN("capacity is equal to 20")
-      {
-        REQUIRE(s.capacity() == 20);
-      }
-
-      THEN("front() return an a")
-      {
-        REQUIRE(s.front() == 'a');
-      }
-
-      THEN("back() return a J")
-      {
-        REQUIRE(s.back() == 'J');
-      }
-
-      THEN("The moved from object's size is 0")
-      {
-        REQUIRE(other.size() == 0);
-      }
-
-      THEN("The moved from object's capacity is 15")
-      {
-        REQUIRE(other.capacity() == 15);
-      }
-
-      THEN("c_str() on the moved from object points to a null byte")
-      {
-        REQUIRE(*other.c_str() == '\0');
-      }
-    }
-  }
-}
-
-SCENARIO("Basic string assignment", "[string]")
-{
-  GIVEN("Two short strings")
-  {
-    auto s1 = char_string{"abcd"};
-    auto s2 = char_string{"defghij"};
-
-    WHEN("copy assigning the shorter to the longer one")
-    {
-      s2 = s1;
-
-      THEN("the new length of the longer one is equal to the length of the shorter one")
-      {
-        REQUIRE(s2.length() == s1.length());
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
-      }
-    }
-
-    WHEN("copy assigning the longer to the shorter one")
-    {
-      s1 = s2;
-
-      THEN("the new length of the shorter one is equal to the length of the longer one")
-      {
-        REQUIRE(s1.length() == s2.length());
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
-      }
-    }
-
-    WHEN("move assigning the shorter to the longer one")
-    {
-      s2 = std::move(s1);
-
-      THEN("the new length of the longer one is equal to the original length of the shorter one")
-      {
-        REQUIRE(s2.length() == 4);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s1.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s1.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-    }
-
-    WHEN("move assigning the longer to the shorter one")
-    {
-      s1 = std::move(s2);
-
-      THEN("the new length of the shorter one is equal to the original length of the longer one")
-      {
-        REQUIRE(s1.length() == 7);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s2.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s1.capacity() == 15);
-      }
-    }
-  }
-
-  GIVEN("One short and one long string")
-  {
-    auto s1 = char_string{"abcd"};
-    auto s2 = char_string{"ABCDEFGHIJabcdefghij"};
-
-    WHEN("copy assigning the shorter to the longer one")
-    {
-      s2 = s1;
-
-      THEN("the new length of the longer one is equal to the length of the shorter one")
-      {
-        REQUIRE(s2.length() == s1.length());
-      }
-
-      THEN("the new capacity of the longer one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
-      }
-    }
-
-    WHEN("copy assigning the longer to the shorter one")
-    {
-      s1 = s2;
-
-      THEN("the new length of the shorter one is equal to the length of the longer one")
-      {
-        REQUIRE(s1.length() == s2.length());
-      }
-
-      THEN("the new capacity of the shorter one is 20")
-      {
-        REQUIRE(s1.capacity() == 20);
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
-      }
-    }
-
-    WHEN("move assigning the shorter to the longer one")
-    {
-      s2 = std::move(s1);
-
-      THEN("the new length of the longer one is equal to the original length of the shorter one")
-      {
-        REQUIRE(s2.length() == 4);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s1.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s1.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-    }
-
-    WHEN("move assigning the longer to the shorter one")
-    {
-      s1 = std::move(s2);
-
-      THEN("the new length of the shorter one is equal to the original length of the longer one")
-      {
-        REQUIRE(s1.length() == 20);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s2.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s1.capacity() == 20);
-      }
-    }
-  }
-
-  GIVEN("Two long strings")
-  {
-    auto s1 = char_string{"abcdefghijABCDEFGH"};
-    auto s2 = char_string{"ABCDEFGHIJabcdefghij"};
-
-    WHEN("copy assigning the shorter to the longer one")
-    {
-      s2 = s1;
-
-      THEN("the new length of the longer one is equal to the length of the shorter one")
-      {
-        REQUIRE(s2.length() == s1.length());
-      }
-
-      THEN("the new capacity of the longer one is still 20")
-      {
-        REQUIRE(s2.capacity() == 20);
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
-      }
-    }
-
-    WHEN("copy assigning the longer to the shorter one")
-    {
-      s1 = s2;
-
-      THEN("the new length of the shorter one is equal to the length of the longer one")
-      {
-        REQUIRE(s1.length() == s2.length());
-      }
-
-      THEN("the new capacity of the shorter one is 20")
-      {
-        REQUIRE(s1.capacity() == 20);
-      }
-
-      THEN("the underlying data of the two is identical")
-      {
-        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
-      }
-    }
-
-    WHEN("move assigning the shorter to the longer one")
-    {
-      s2 = std::move(s1);
-
-      THEN("the new length of the longer one is equal to the original length of the shorter one")
-      {
-        REQUIRE(s2.length() == 18);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s1.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s1.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s2.capacity() == 18);
-      }
-    }
-
-    WHEN("move assigning the longer to the shorter one")
-    {
-      s1 = std::move(s2);
-
-      THEN("the new length of the shorter one is equal to the original length of the longer one")
-      {
-        REQUIRE(s1.length() == 20);
-      }
-
-      THEN("the length of the moved from one is 0")
-      {
-        REQUIRE(s2.length() == 0);
-      }
-
-      THEN("the capacity of the moved from one is 15")
-      {
-        REQUIRE(s2.capacity() == 15);
-      }
-
-      THEN("the capacity of the moved to one is 15")
-      {
-        REQUIRE(s1.capacity() == 20);
-      }
-    }
-  }
-
-  GIVEN("An short string")
-  {
-    auto s = char_string{"abcd"};
-
-    WHEN("assigning a new, shorter c-style string of length 3")
-    {
-      s = "def";
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning a new, longer, c-style string of length 5")
-    {
-      s = "defgh";
-
-      THEN("the length is equal to 5")
-      {
-        REQUIRE(s.length() == 5);
-      }
-    }
-
-    WHEN("assigning a new, longer, c-style string of length 20")
-    {
-      s = "ABCDEFGHIJabcdefghij";
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-    }
-
-    WHEN("assigning a single character")
-    {
-      s = 'z';
-
-      THEN("the length is equal to 1")
-      {
-        REQUIRE(s.length() == 1);
-      }
-    }
-
-    WHEN("assigning an shorter initializer list of length 3")
-    {
-      s = {'d', 'e', 'f'};
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning an longer initializer list of length 5")
-    {
-      s = {'d', 'e', 'f', 'g', 'h'};
-
-      THEN("the length is equal to 5")
-      {
-        REQUIRE(s.length() == 5);
-      }
-    }
-
-    WHEN("assigning an longer initializer list of length 20")
-    {
-      s = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'};
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-    }
-
-    WHEN("assigning from a shorter string view of length 3")
-    {
-      using namespace std::string_view_literals;
-
-      s = "def"sv;
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning from a longer string view of length 5")
-    {
-      using namespace std::string_view_literals;
-
-      s = "defgh"sv;
-
-      THEN("the length is equal to 5")
-      {
-        REQUIRE(s.length() == 5);
-      }
-    }
-
-    WHEN("assigning from a longer string view of length 20")
-    {
-      using namespace std::string_view_literals;
-
-      s = "ABCDEFGHIJabcdefghij"sv;
-
-      THEN("the length is equal to 20")
-      {
-        REQUIRE(s.length() == 20);
-      }
-    }
-  }
-
-  GIVEN("An long string")
-  {
-    auto s = char_string{"abcdefghijABCDEFGHIJ"};
-
-    WHEN("assigning a new, shorter c-style string of length 3")
-    {
-      s = "def";
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning a new, longer, c-style string of length 22")
-    {
-      s = "ABCDEFGHIJabcdefghijkl";
-
-      THEN("the length is equal to 22")
-      {
-        REQUIRE(s.length() == 22);
-      }
-    }
-
-    WHEN("assigning a single character")
-    {
-      s = 'z';
-
-      THEN("the length is equal to 1")
-      {
-        REQUIRE(s.length() == 1);
-      }
-    }
-
-    WHEN("assigning an shorter initializer list of length 3")
-    {
-      s = {'d', 'e', 'f'};
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning an longer initializer list of length 22")
-    {
-      s = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'a',
-           'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l'};
-
-      THEN("the length is equal to 22")
-      {
-        REQUIRE(s.length() == 22);
-      }
-    }
-
-    WHEN("assigning from a shorter string view of length 3")
-    {
-      using namespace std::string_view_literals;
-
-      s = "def"sv;
-
-      THEN("the length is equal to 3")
-      {
-        REQUIRE(s.length() == 3);
-      }
-    }
-
-    WHEN("assigning from a longer string view of length 22")
-    {
-      using namespace std::string_view_literals;
-
-      s = "ABCDEFGHIJabcdefghijkl"sv;
-
-      THEN("the length is equal to 22")
-      {
-        REQUIRE(s.length() == 22);
-      }
-    }
-  }
-}
-
-SCENARIO("Basic string of char modifiers", "[string]")
-{
-  GIVEN("A short string")
-  {
-    auto s = char_string{"abcd"};
-    auto old_capacity = s.capacity();
-    auto old_size = s.size();
-    auto old_data = s.data();
-
-    WHEN("reserving a smaller capacity")
-    {
-      s.reserve(1);
-
-      THEN("the capacity does not change")
-      {
-        REQUIRE(s.capacity() == old_capacity);
-      }
-
-      THEN("the content stays the same")
-      {
-        REQUIRE(s == "abcd");
-      }
-
-      THEN("the size stays the same")
-      {
-        REQUIRE(s.size() == old_size);
-      }
-
-      THEN("the data pointer stays the same")
-      {
-        REQUIRE(s.data() == old_data);
-      }
-    }
-
-    WHEN("reserving equal capacity")
-    {
-      s.reserve(old_capacity);
-
-      THEN("the capacity does not change")
-      {
-        REQUIRE(s.capacity() == old_capacity);
-      }
-
-      THEN("the content stays the same")
-      {
-        REQUIRE(s == "abcd");
-      }
-
-      THEN("the size stays the same")
-      {
-        REQUIRE(s.size() == old_size);
-      }
-
-      THEN("the data pointer stays the same")
-      {
-        REQUIRE(static_cast<void const *>(s.data()) == static_cast<void const *>(old_data));
-      }
-    }
-
-    WHEN("reserving larger capacity")
-    {
-      s.reserve(old_capacity + 1);
-
-      THEN("the capacity increases")
-      {
-        REQUIRE(s.capacity() >= old_capacity + 1);
-      }
-
-      THEN("the content stays the same")
-      {
-        REQUIRE(s == "abcd");
-      }
-
-      THEN("the size stays the same")
-      {
-        REQUIRE(s.size() == old_size);
-      }
-
-      THEN("the data pointer changes")
-      {
-        REQUIRE(s.data() != old_data);
-      }
-    }
-  }
-}
diff --git a/libs/kstd/kstd/string.test.cpp b/libs/kstd/kstd/string.test.cpp
index b81cd3a..e5925aa 100644
--- a/libs/kstd/kstd/string.test.cpp
+++ b/libs/kstd/kstd/string.test.cpp
@@ -1,158 +1,1959 @@
 #include <kstd/string>
 
+#include <kstd/allocator>
+#include <kstd/test_support/os_panic.hpp>
+
 #include <catch2/catch_test_macros.hpp>
 
 #include <algorithm>
 #include <cstring>
+#include <forward_list>
+#include <iterator>
+#include <memory>
+#include <sstream>
 #include <string_view>
+#include <type_traits>
+#include <utility>
+
+TEST_CASE("String static interface")
+{
+  REQUIRE(std::is_same_v<kstd::string::traits_type, kstd::char_traits<char>>);
+  REQUIRE(std::is_same_v<kstd::string::value_type, char>);
+  REQUIRE(std::is_same_v<kstd::string::allocator_type, kstd::allocator<char>>);
+  REQUIRE(std::is_same_v<kstd::string::size_type, std::allocator_traits<kstd::allocator<char>>::size_type>);
+  REQUIRE(std::is_same_v<kstd::string::difference_type, std::allocator_traits<kstd::allocator<char>>::difference_type>);
+  REQUIRE(std::is_same_v<kstd::string::reference, char &>);
+  REQUIRE(std::is_same_v<kstd::string::const_reference, char const &>);
+  REQUIRE(std::is_same_v<kstd::string::pointer, std::allocator_traits<kstd::allocator<char>>::pointer>);
+  REQUIRE(std::is_same_v<kstd::string::const_pointer, std::allocator_traits<kstd::allocator<char>>::const_pointer>);
+  REQUIRE(std::is_same_v<kstd::string::iterator, char *>);
+  REQUIRE(std::is_same_v<kstd::string::const_iterator, char const *>);
+  REQUIRE(std::is_same_v<kstd::string::reverse_iterator, std::reverse_iterator<char *>>);
+  REQUIRE(std::is_same_v<kstd::string::const_reverse_iterator, std::reverse_iterator<char const *>>);
+
+  REQUIRE(kstd::string::npos == kstd::string::size_type(-1));
+}
 
 SCENARIO("String initialization and construction", "[string]")
 {
-  GIVEN("Nothing")
+  GIVEN("An empty context")
   {
-    WHEN("constructing an empty string")
+    WHEN("constructing by default")
     {
-      auto str = kstd::string{};
+      auto s = kstd::string{};
 
-      THEN("the size is zero and therefore the string is empty")
+      THEN("the string is empty")
       {
-        REQUIRE(str.empty());
-        REQUIRE(str.size() == 0);
+        REQUIRE(s.empty());
+      }
+
+      THEN("the size is equal to zero")
+      {
+        REQUIRE(s.size() == 0);
+      }
+
+      THEN("the length is equal to zero")
+      {
+        REQUIRE(s.length() == 0);
+      }
+
+      THEN("at raises a panic")
+      {
+        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
+      }
+
+      THEN("data returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.data() == '\0');
+      }
+
+      THEN("c_str returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.c_str() == '\0');
+      }
+
+      THEN("the string is convertible to an empty string view")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.empty());
+      }
+    }
+
+    WHEN("constructing with 10 copies of the letter 'a'")
+    {
+      auto s = kstd::string{10, 'a'};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 10")
+      {
+        REQUIRE(s.size() == 10);
+      }
+
+      THEN("the length is equal to 10")
+      {
+        REQUIRE(s.length() == 10);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns a")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'a');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns a")
+      {
+        REQUIRE(s[s.size() - 1] == 'a');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns a")
+      {
+        REQUIRE(s.back() == 'a');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 10")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 10);
+      }
+
+      THEN("the string converts to a string view of length 10")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 10);
+      }
+    }
+
+    WHEN("constructing with 20 copies of the letter 'a'")
+    {
+      auto s = kstd::string{20, 'a'};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns a")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'a');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns a")
+      {
+        REQUIRE(s[s.size() - 1] == 'a');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns a")
+      {
+        REQUIRE(s.back() == 'a');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing with an input iterator pair of 10 characters")
+    {
+      auto source = std::istringstream{"abcdefghij"};
+      auto s = kstd::string{std::istream_iterator<char>{source}, std::istream_iterator<char>{}};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 10")
+      {
+        REQUIRE(s.size() == 10);
+      }
+
+      THEN("the length is equal to 10")
+      {
+        REQUIRE(s.length() == 10);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns j")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'j');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns j")
+      {
+        REQUIRE(s[s.size() - 1] == 'j');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns j")
+      {
+        REQUIRE(s.back() == 'j');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 10")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 10);
+      }
+
+      THEN("the string converts to a string view of length 10")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 10);
+      }
+    }
+
+    WHEN("constructing with an input iterator pair of 20 characters")
+    {
+      auto source = std::istringstream{"abcdefghijABCDEFGHIJ"};
+      auto s = kstd::string{std::istream_iterator<char>{source}, std::istream_iterator<char>{}};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is greater than or equal to 20")
+      {
+        REQUIRE(s.capacity() >= 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing with a forward iterator pair of 10 characters")
+    {
+      auto source = std::forward_list{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'};
+      auto s = kstd::string{source.cbegin(), source.cend()};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 10")
+      {
+        REQUIRE(s.size() == 10);
+      }
+
+      THEN("the length is equal to 10")
+      {
+        REQUIRE(s.length() == 10);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns j")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'j');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns j")
+      {
+        REQUIRE(s[s.size() - 1] == 'j');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns j")
+      {
+        REQUIRE(s.back() == 'j');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 10")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 10);
+      }
+
+      THEN("the string converts to a string view of length 10")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 10);
+      }
+    }
+
+    WHEN("constructing with a forward iterator pair of 20 characters")
+    {
+      auto source = std::forward_list{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
+                                      'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
+      auto s = kstd::string{source.cbegin(), source.cend()};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
       }
 
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing from a null pointer with zero size")
+    {
+      auto s = kstd::string{static_cast<char const *>(nullptr), 0};
+
       THEN("the string is empty")
       {
-        REQUIRE(str == std::string_view{});
+        REQUIRE(s.empty());
+      }
+
+      THEN("the size is equal to 0")
+      {
+        REQUIRE(s.size() == 0);
+      }
+
+      THEN("the length is equal to 0")
+      {
+        REQUIRE(s.length() == 0);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at raises a panic")
+      {
+        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
+      }
+
+      THEN("data returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.data() == '\0');
+      }
+
+      THEN("c_str returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.c_str() == '\0');
+      }
+
+      THEN("the string is convertible to an empty string view")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.empty());
+      }
+    }
+
+    WHEN("constructing from a from a null pointer and non-zero size")
+    {
+      THEN("a panic is raised")
+      {
+        REQUIRE_THROWS_AS((kstd::string{static_cast<char const *>(nullptr), 1}), kstd::tests::os_panic);
+      }
+    }
+
+    WHEN("constructing from a non-null pointer and zero size")
+    {
+      auto ptr = "abcd";
+      auto s = kstd::string{ptr, 0};
+
+      THEN("the string is empty")
+      {
+        REQUIRE(s.empty());
+      }
+
+      THEN("the size is equal to 0")
+      {
+        REQUIRE(s.size() == 0);
+      }
+
+      THEN("the length is equal to 0")
+      {
+        REQUIRE(s.length() == 0);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at raises a panic")
+      {
+        REQUIRE_THROWS_AS(s.at(0), kstd::tests::os_panic);
+      }
+
+      THEN("data returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.data() == '\0');
+      }
+
+      THEN("c_str returns a pointer poiting to a null byte")
+      {
+        REQUIRE(*s.c_str() == '\0');
+      }
+
+      THEN("the string is convertible to an empty string view")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.empty());
+      }
+    }
+
+    WHEN("constructing from a non-null pointer and a size of 4")
+    {
+      auto ptr = "abcd";
+      auto s = kstd::string{ptr, 4};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 4")
+      {
+        REQUIRE(s.size() == 4);
+      }
+
+      THEN("the length is equal to 4")
+      {
+        REQUIRE(s.length() == 4);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns d")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'd');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns d")
+      {
+        REQUIRE(s[s.size() - 1] == 'd');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns d")
+      {
+        REQUIRE(s.back() == 'd');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 4")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 4);
+      }
+
+      THEN("the string converts to a string view of length 4")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 4);
+      }
+    }
+
+    WHEN("constructing from a non-null pointer and a size of 20")
+    {
+      auto ptr = "abcdefghijABCDEFGHIJ";
+      auto s = kstd::string{ptr, 20};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing from a C-style string of length 4")
+    {
+      auto ptr = "abcd";
+      auto s = kstd::string{ptr};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 4")
+      {
+        REQUIRE(s.size() == 4);
+      }
+
+      THEN("the length is equal to 4")
+      {
+        REQUIRE(s.length() == 4);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns d")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'd');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns d")
+      {
+        REQUIRE(s[s.size() - 1] == 'd');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns d")
+      {
+        REQUIRE(s.back() == 'd');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 4")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 4);
+      }
+
+      THEN("the string converts to a string view of length 4")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 4);
+      }
+    }
+
+    WHEN("constructing from a C-style string of length 20")
+    {
+      auto ptr = "abcdefghijABCDEFGHIJ";
+      auto s = kstd::string{ptr};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing from a string view of length 4")
+    {
+      using namespace std::string_view_literals;
+
+      auto view = "abcd"sv;
+      auto s = kstd::string{view};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 4")
+      {
+        REQUIRE(s.size() == 4);
+      }
+
+      THEN("the length is equal to 4")
+      {
+        REQUIRE(s.length() == 4);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns d")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'd');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns d")
+      {
+        REQUIRE(s[s.size() - 1] == 'd');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns d")
+      {
+        REQUIRE(s.back() == 'd');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 4")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 4);
+      }
+
+      THEN("the string converts to a string view of length 4")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 4);
+      }
+    }
+
+    WHEN("constructing from a string view of length 20")
+    {
+      using namespace std::string_view_literals;
+
+      auto view = "abcdefghijABCDEFGHIJ"sv;
+      auto s = kstd::string{view};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+
+      THEN("the capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("at(0) returns a")
+      {
+        REQUIRE(s.at(0) == 'a');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns a")
+      {
+        REQUIRE(s[0] == 'a');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.data() == 'a');
+      }
+
+      THEN("c_str returns a pointer pointing to an a")
+      {
+        REQUIRE(*s.c_str() == 'a');
+      }
+
+      THEN("c_str points to the start of a c-string of length 20")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 20);
+      }
+
+      THEN("the string converts to a string view of length 20")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 20);
+      }
+    }
+
+    WHEN("constructing from a substring of a string view of length 4")
+    {
+      using namespace std::string_view_literals;
+
+      auto view = "abcd"sv;
+      auto s = kstd::string{view, 1, 4};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 3")
+      {
+        REQUIRE(s.size() == 3);
+      }
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+
+      THEN("the capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("at(0) returns b")
+      {
+        REQUIRE(s.at(0) == 'b');
+      }
+
+      THEN("at(size() - 1) returns d")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'd');
+      }
+
+      THEN("[0] returns b")
+      {
+        REQUIRE(s[0] == 'b');
+      }
+
+      THEN("[size() - 1] returns d")
+      {
+        REQUIRE(s[s.size() - 1] == 'd');
+      }
+
+      THEN("front returns b")
+      {
+        REQUIRE(s.front() == 'b');
+      }
+
+      THEN("back returns d")
+      {
+        REQUIRE(s.back() == 'd');
+      }
+
+      THEN("data returns a pointer pointing to an b")
+      {
+        REQUIRE(*s.data() == 'b');
+      }
+
+      THEN("c_str returns a pointer pointing to an b")
+      {
+        REQUIRE(*s.c_str() == 'b');
+      }
+
+      THEN("c_str points to the start of a c-string of length 3")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 3);
+      }
+
+      THEN("the string converts to a string view of length 3")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 3);
+      }
+    }
+
+    WHEN("constructing from a substring of a string view of length 20")
+    {
+      using namespace std::string_view_literals;
+
+      auto view = "abcdefghijABCDEFGHIJ"sv;
+      auto s = kstd::string{view, 1, 20};
+
+      THEN("the string is not empty")
+      {
+        REQUIRE_FALSE(s.empty());
+      }
+
+      THEN("the size is equal to 19")
+      {
+        REQUIRE(s.size() == 19);
+      }
+
+      THEN("the length is equal to 19")
+      {
+        REQUIRE(s.length() == 19);
+      }
+
+      THEN("the capacity is equal to 19")
+      {
+        REQUIRE(s.capacity() == 19);
+      }
+
+      THEN("at(0) returns b")
+      {
+        REQUIRE(s.at(0) == 'b');
+      }
+
+      THEN("at(size() - 1) returns J")
+      {
+        REQUIRE(s.at(s.size() - 1) == 'J');
+      }
+
+      THEN("[0] returns b")
+      {
+        REQUIRE(s[0] == 'b');
+      }
+
+      THEN("[size() - 1] returns J")
+      {
+        REQUIRE(s[s.size() - 1] == 'J');
+      }
+
+      THEN("front returns b")
+      {
+        REQUIRE(s.front() == 'b');
+      }
+
+      THEN("back returns J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("data returns a pointer pointing to an b")
+      {
+        REQUIRE(*s.data() == 'b');
+      }
+
+      THEN("c_str returns a pointer pointing to an b")
+      {
+        REQUIRE(*s.c_str() == 'b');
+      }
+
+      THEN("c_str points to the start of a c-string of length 19")
+      {
+        REQUIRE(std::strlen(s.c_str()) == 19);
+      }
+
+      THEN("the string converts to a string view of length 19")
+      {
+        auto view = static_cast<std::string_view>(s);
+        REQUIRE(view.length() == 19);
       }
     }
   }
 
-  GIVEN("A string view")
+  GIVEN("An existing short string, of length 10")
   {
-    auto view = std::string_view{"Blub Blub"};
+    auto other = kstd::string{"abcdefghij"};
+
+    WHEN("constructing by copy")
+    {
+      auto s = other;
+
+      THEN("the sizes are identical")
+      {
+        REQUIRE(s.size() == other.size());
+      }
 
-    WHEN("constructing a string from string_view")
+      THEN("the capacities are idendtical")
+      {
+        REQUIRE(s.capacity() == other.capacity());
+      }
+
+      THEN("the underlying strings are identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s.data(), other.data()));
+      }
+    }
+
+    WHEN("constructing by move")
     {
-      auto str = kstd::string{view};
+      auto s = std::move(other);
+
+      THEN("size is equal to 10")
+      {
+        REQUIRE(s.size() == 10);
+      }
+
+      THEN("capacity is equal to 15")
+      {
+        REQUIRE(s.capacity() == 15);
+      }
+
+      THEN("front() return an a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back() return a j")
+      {
+        REQUIRE(s.back() == 'j');
+      }
 
-      THEN("the string is not empty and has the same size as the view")
+      THEN("The moved from object's size is 0")
       {
-        REQUIRE_FALSE(str.empty());
-        REQUIRE(str.size() == view.size());
+        REQUIRE(other.size() == 0);
       }
 
-      THEN("the string contains the same characters as the view")
+      THEN("The moved from object's capacity is 15")
       {
-        REQUIRE(str == view);
+        REQUIRE(other.capacity() == 15);
+      }
+
+      THEN("c_str() on the moved from object points to a null byte")
+      {
+        REQUIRE(*other.c_str() == '\0');
       }
     }
   }
 
-  GIVEN("A C-style string")
+  GIVEN("An existing short string, of length 20")
   {
-    auto c_str = "Blub Blub";
+    auto other = kstd::string{"abcdefghijABCDEFGHIJ"};
 
-    WHEN("constructing a string from the C-style string")
+    WHEN("constructing by copy")
     {
-      auto str = kstd::string{c_str};
+      auto s = other;
 
-      THEN("the string is not empty and has the same size as the C-style string")
+      THEN("the sizes are identical")
       {
-        REQUIRE_FALSE(str.empty());
-        REQUIRE(str.size() == std::strlen(c_str));
+        REQUIRE(s.size() == other.size());
       }
 
-      THEN("the string contains the same characters as the C-style string")
+      THEN("the capacities are idendtical")
       {
-        REQUIRE(str == c_str);
+        REQUIRE(s.capacity() == other.capacity());
+      }
+
+      THEN("the underlying strings are identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s.data(), other.data()));
+      }
+    }
+
+    WHEN("constructing by move")
+    {
+      auto s = std::move(other);
+
+      THEN("size is equal to 20")
+      {
+        REQUIRE(s.size() == 20);
+      }
+
+      THEN("capacity is equal to 20")
+      {
+        REQUIRE(s.capacity() == 20);
+      }
+
+      THEN("front() return an a")
+      {
+        REQUIRE(s.front() == 'a');
+      }
+
+      THEN("back() return a J")
+      {
+        REQUIRE(s.back() == 'J');
+      }
+
+      THEN("The moved from object's size is 0")
+      {
+        REQUIRE(other.size() == 0);
+      }
+
+      THEN("The moved from object's capacity is 15")
+      {
+        REQUIRE(other.capacity() == 15);
+      }
+
+      THEN("c_str() on the moved from object points to a null byte")
+      {
+        REQUIRE(*other.c_str() == '\0');
       }
     }
   }
+}
 
-  GIVEN("A character")
+SCENARIO("String assignment", "[string]")
+{
+  GIVEN("Two short strings")
   {
-    auto ch = 'x';
+    auto s1 = kstd::string{"abcd"};
+    auto s2 = kstd::string{"defghij"};
+
+    WHEN("copy assigning the shorter to the longer one")
+    {
+      s2 = s1;
+
+      THEN("the new length of the longer one is equal to the length of the shorter one")
+      {
+        REQUIRE(s2.length() == s1.length());
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
+      }
+    }
+
+    WHEN("copy assigning the longer to the shorter one")
+    {
+      s1 = s2;
 
-    WHEN("constructing a string from the character")
+      THEN("the new length of the shorter one is equal to the length of the longer one")
+      {
+        REQUIRE(s1.length() == s2.length());
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
+      }
+    }
+
+    WHEN("move assigning the shorter to the longer one")
+    {
+      s2 = std::move(s1);
+
+      THEN("the new length of the longer one is equal to the original length of the shorter one")
+      {
+        REQUIRE(s2.length() == 4);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s1.length() == 0);
+      }
+
+      THEN("the capacity of the moved from one is 15")
+      {
+        REQUIRE(s1.capacity() == 15);
+      }
+
+      THEN("the capacity of the moved to one is 15")
+      {
+        REQUIRE(s2.capacity() == 15);
+      }
+    }
+
+    WHEN("move assigning the longer to the shorter one")
     {
-      auto str = kstd::string{ch};
+      s1 = std::move(s2);
+
+      THEN("the new length of the shorter one is equal to the original length of the longer one")
+      {
+        REQUIRE(s1.length() == 7);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s2.length() == 0);
+      }
 
-      THEN("the string is not empty and has size 1")
+      THEN("the capacity of the moved from one is 15")
       {
-        REQUIRE_FALSE(str.empty());
-        REQUIRE(str.size() == 1);
+        REQUIRE(s2.capacity() == 15);
       }
 
-      THEN("the string contains the same character as the given character")
+      THEN("the capacity of the moved to one is 15")
       {
-        REQUIRE(str == std::string_view{&ch, 1});
+        REQUIRE(s1.capacity() == 15);
       }
     }
   }
 
-  GIVEN("Another string")
+  GIVEN("One short and one long string")
   {
-    auto other = kstd::string{"Blub Blub"};
+    auto s1 = kstd::string{"abcd"};
+    auto s2 = kstd::string{"ABCDEFGHIJabcdefghij"};
 
-    WHEN("copy constructing a new string")
+    WHEN("copy assigning the shorter to the longer one")
     {
-      auto str = kstd::string{other};
+      s2 = s1;
 
-      THEN("the new string contains the same characters as the original")
+      THEN("the new length of the longer one is equal to the length of the shorter one")
       {
-        REQUIRE(static_cast<std::string_view>(str) == static_cast<std::string_view>(other));
+        REQUIRE(s2.length() == s1.length());
+      }
+
+      THEN("the new capacity of the longer one is 15")
+      {
+        REQUIRE(s2.capacity() == 15);
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
       }
     }
 
-    auto str = kstd::string{"Blub"};
+    WHEN("copy assigning the longer to the shorter one")
+    {
+      s1 = s2;
 
-    WHEN("copy assigning another string")
+      THEN("the new length of the shorter one is equal to the length of the longer one")
+      {
+        REQUIRE(s1.length() == s2.length());
+      }
+
+      THEN("the new capacity of the shorter one is 20")
+      {
+        REQUIRE(s1.capacity() == 20);
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
+      }
+    }
+
+    WHEN("move assigning the shorter to the longer one")
     {
-      auto other = kstd::string{"Blub Blub"};
-      str = other;
+      s2 = std::move(s1);
 
-      THEN("the string contains the same characters as the assigned string")
+      THEN("the new length of the longer one is equal to the original length of the shorter one")
       {
-        REQUIRE(static_cast<std::string_view>(str) == static_cast<std::string_view>(other));
+        REQUIRE(s2.length() == 4);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s1.length() == 0);
+      }
+
+      THEN("the capacity of the moved from one is 15")
+      {
+        REQUIRE(s1.capacity() == 15);
+      }
+
+      THEN("the capacity of the moved to one is 15")
+      {
+        REQUIRE(s2.capacity() == 15);
+      }
+    }
+
+    WHEN("move assigning the longer to the shorter one")
+    {
+      s1 = std::move(s2);
+
+      THEN("the new length of the shorter one is equal to the original length of the longer one")
+      {
+        REQUIRE(s1.length() == 20);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s2.length() == 0);
+      }
+
+      THEN("the capacity of the moved from one is 15")
+      {
+        REQUIRE(s2.capacity() == 15);
+      }
+
+      THEN("the capacity of the moved to one is 15")
+      {
+        REQUIRE(s1.capacity() == 20);
       }
     }
   }
 
-  GIVEN("A string")
+  GIVEN("Two long strings")
   {
-    auto str = kstd::string{"Hello"};
+    auto s1 = kstd::string{"abcdefghijABCDEFGH"};
+    auto s2 = kstd::string{"ABCDEFGHIJabcdefghij"};
 
-    WHEN("copy assigning a string view")
+    WHEN("copy assigning the shorter to the longer one")
     {
-      auto view = std::string_view{"Hello, world!"};
-      str = view;
+      s2 = s1;
 
-      THEN("the string contains the same characters as the assigned view")
+      THEN("the new length of the longer one is equal to the length of the shorter one")
       {
-        REQUIRE(str == view);
+        REQUIRE(s2.length() == s1.length());
+      }
+
+      THEN("the new capacity of the longer one is still 20")
+      {
+        REQUIRE(s2.capacity() == 20);
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s1.data(), s2.data()));
+      }
+    }
+
+    WHEN("copy assigning the longer to the shorter one")
+    {
+      s1 = s2;
+
+      THEN("the new length of the shorter one is equal to the length of the longer one")
+      {
+        REQUIRE(s1.length() == s2.length());
+      }
+
+      THEN("the new capacity of the shorter one is 20")
+      {
+        REQUIRE(s1.capacity() == 20);
+      }
+
+      THEN("the underlying data of the two is identical")
+      {
+        REQUIRE_FALSE(std::strcmp(s2.data(), s1.data()));
+      }
+    }
+
+    WHEN("move assigning the shorter to the longer one")
+    {
+      s2 = std::move(s1);
+
+      THEN("the new length of the longer one is equal to the original length of the shorter one")
+      {
+        REQUIRE(s2.length() == 18);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s1.length() == 0);
+      }
+
+      THEN("the capacity of the moved from one is 15")
+      {
+        REQUIRE(s1.capacity() == 15);
+      }
+
+      THEN("the capacity of the moved to one is 15")
+      {
+        REQUIRE(s2.capacity() == 18);
+      }
+    }
+
+    WHEN("move assigning the longer to the shorter one")
+    {
+      s1 = std::move(s2);
+
+      THEN("the new length of the shorter one is equal to the original length of the longer one")
+      {
+        REQUIRE(s1.length() == 20);
+      }
+
+      THEN("the length of the moved from one is 0")
+      {
+        REQUIRE(s2.length() == 0);
+      }
+
+      THEN("the capacity of the moved from one is 15")
+      {
+        REQUIRE(s2.capacity() == 15);
+      }
+
+      THEN("the capacity of the moved to one is 15")
+      {
+        REQUIRE(s1.capacity() == 20);
       }
     }
   }
 
-  GIVEN("A string")
+  GIVEN("An short string")
   {
-    auto str = kstd::string{"Hello"};
+    auto s = kstd::string{"abcd"};
+
+    WHEN("assigning a new, shorter c-style string of length 3")
+    {
+      s = "def";
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning a new, longer, c-style string of length 5")
+    {
+      s = "defgh";
+
+      THEN("the length is equal to 5")
+      {
+        REQUIRE(s.length() == 5);
+      }
+    }
+
+    WHEN("assigning a new, longer, c-style string of length 20")
+    {
+      s = "ABCDEFGHIJabcdefghij";
 
-    WHEN("copy assigning a C-style string")
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+    }
+
+    WHEN("assigning a single character")
     {
-      auto c_str = "Hello, world!";
-      str = c_str;
+      s = 'z';
 
-      THEN("the string contains the same characters as the assigned C-style string")
+      THEN("the length is equal to 1")
       {
-        REQUIRE(str == c_str);
+        REQUIRE(s.length() == 1);
+      }
+    }
+
+    WHEN("assigning an shorter initializer list of length 3")
+    {
+      s = {'d', 'e', 'f'};
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning an longer initializer list of length 5")
+    {
+      s = {'d', 'e', 'f', 'g', 'h'};
+
+      THEN("the length is equal to 5")
+      {
+        REQUIRE(s.length() == 5);
+      }
+    }
+
+    WHEN("assigning an longer initializer list of length 20")
+    {
+      s = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'};
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+    }
+
+    WHEN("assigning from a shorter string view of length 3")
+    {
+      using namespace std::string_view_literals;
+
+      s = "def"sv;
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning from a longer string view of length 5")
+    {
+      using namespace std::string_view_literals;
+
+      s = "defgh"sv;
+
+      THEN("the length is equal to 5")
+      {
+        REQUIRE(s.length() == 5);
+      }
+    }
+
+    WHEN("assigning from a longer string view of length 20")
+    {
+      using namespace std::string_view_literals;
+
+      s = "ABCDEFGHIJabcdefghij"sv;
+
+      THEN("the length is equal to 20")
+      {
+        REQUIRE(s.length() == 20);
+      }
+    }
+  }
+
+  GIVEN("An long string")
+  {
+    auto s = kstd::string{"abcdefghijABCDEFGHIJ"};
+
+    WHEN("assigning a new, shorter c-style string of length 3")
+    {
+      s = "def";
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning a new, longer, c-style string of length 22")
+    {
+      s = "ABCDEFGHIJabcdefghijkl";
+
+      THEN("the length is equal to 22")
+      {
+        REQUIRE(s.length() == 22);
+      }
+    }
+
+    WHEN("assigning a single character")
+    {
+      s = 'z';
+
+      THEN("the length is equal to 1")
+      {
+        REQUIRE(s.length() == 1);
+      }
+    }
+
+    WHEN("assigning an shorter initializer list of length 3")
+    {
+      s = {'d', 'e', 'f'};
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning an longer initializer list of length 22")
+    {
+      s = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'a',
+           'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l'};
+
+      THEN("the length is equal to 22")
+      {
+        REQUIRE(s.length() == 22);
+      }
+    }
+
+    WHEN("assigning from a shorter string view of length 3")
+    {
+      using namespace std::string_view_literals;
+
+      s = "def"sv;
+
+      THEN("the length is equal to 3")
+      {
+        REQUIRE(s.length() == 3);
+      }
+    }
+
+    WHEN("assigning from a longer string view of length 22")
+    {
+      using namespace std::string_view_literals;
+
+      s = "ABCDEFGHIJabcdefghijkl"sv;
+
+      THEN("the length is equal to 22")
+      {
+        REQUIRE(s.length() == 22);
       }
     }
   }
 }
 
-SCENARIO("String concatenation", "[string]")
+SCENARIO("String modifiers", "[string]")
 {
+  GIVEN("A short string")
+  {
+    auto s = kstd::string{"abcd"};
+    auto old_capacity = s.capacity();
+    auto old_size = s.size();
+    auto old_data = s.data();
+
+    WHEN("reserving a smaller capacity")
+    {
+      s.reserve(1);
+
+      THEN("the capacity does not change")
+      {
+        REQUIRE(s.capacity() == old_capacity);
+      }
+
+      THEN("the content stays the same")
+      {
+        REQUIRE(s == "abcd");
+      }
+
+      THEN("the size stays the same")
+      {
+        REQUIRE(s.size() == old_size);
+      }
+
+      THEN("the data pointer stays the same")
+      {
+        REQUIRE(s.data() == old_data);
+      }
+    }
+
+    WHEN("reserving equal capacity")
+    {
+      s.reserve(old_capacity);
+
+      THEN("the capacity does not change")
+      {
+        REQUIRE(s.capacity() == old_capacity);
+      }
+
+      THEN("the content stays the same")
+      {
+        REQUIRE(s == "abcd");
+      }
+
+      THEN("the size stays the same")
+      {
+        REQUIRE(s.size() == old_size);
+      }
+
+      THEN("the data pointer stays the same")
+      {
+        REQUIRE(static_cast<void const *>(s.data()) == static_cast<void const *>(old_data));
+      }
+    }
+
+    WHEN("reserving larger capacity")
+    {
+      s.reserve(old_capacity + 1);
+
+      THEN("the capacity increases")
+      {
+        REQUIRE(s.capacity() >= old_capacity + 1);
+      }
+
+      THEN("the content stays the same")
+      {
+        REQUIRE(s == "abcd");
+      }
+
+      THEN("the size stays the same")
+      {
+        REQUIRE(s.size() == old_size);
+      }
+
+      THEN("the data pointer changes")
+      {
+        REQUIRE(s.data() != old_data);
+      }
+    }
+  }
+
   GIVEN("Two strings")
   {
     auto str1 = kstd::string{"Blub"};
@@ -187,21 +1988,6 @@ SCENARIO("String concatenation", "[string]")
         REQUIRE(str1.size() == str2.size() + 4);
       }
     }
-
-    WHEN("using operator+ to concatenate the two strings into a new string")
-    {
-      auto str3 = str1 + str2;
-
-      THEN("the new string contains the characters of both strings concatenated")
-      {
-        REQUIRE(str3 == "Blub Blub");
-      }
-
-      THEN("the size of the new string is the sum of the sizes of both strings")
-      {
-        REQUIRE(str3.size() == str1.size() + str2.size());
-      }
-    }
   }
 
   GIVEN("A string and a string view")
@@ -260,6 +2046,51 @@ SCENARIO("String concatenation", "[string]")
       }
     }
   }
+
+  GIVEN("A non-empty string")
+  {
+    auto str = kstd::string{"Blub Blub"};
+
+    WHEN("clearing the string")
+    {
+      str.clear();
+
+      THEN("the string is empty and has size zero")
+      {
+        REQUIRE(str.empty());
+        REQUIRE(str.size() == 0);
+      }
+
+      THEN("the string contains no characters")
+      {
+        REQUIRE(str == std::string_view{});
+      }
+    }
+  }
+}
+
+SCENARIO("String concatenation", "[string]")
+{
+  GIVEN("Two strings")
+  {
+    auto str1 = kstd::string{"Blub"};
+    auto str2 = kstd::string{" Blub"};
+
+    WHEN("using operator+ to concatenate the two strings into a new string")
+    {
+      auto str3 = str1 + str2;
+
+      THEN("the new string contains the characters of both strings concatenated")
+      {
+        REQUIRE(str3 == "Blub Blub");
+      }
+
+      THEN("the size of the new string is the sum of the sizes of both strings")
+      {
+        REQUIRE(str3.size() == str1.size() + str2.size());
+      }
+    }
+  }
 }
 
 SCENARIO("String conversion and comparison", "[string]")
@@ -317,30 +2148,6 @@ SCENARIO("String conversion and comparison", "[string]")
   }
 }
 
-SCENARIO("String clearing", "[string]")
-{
-  GIVEN("A non-empty string")
-  {
-    auto str = kstd::string{"Blub Blub"};
-
-    WHEN("clearing the string")
-    {
-      str.clear();
-
-      THEN("the string is empty and has size zero")
-      {
-        REQUIRE(str.empty());
-        REQUIRE(str.size() == 0);
-      }
-
-      THEN("the string contains no characters")
-      {
-        REQUIRE(str == std::string_view{});
-      }
-    }
-  }
-}
-
 SCENARIO("String iteration", "[string]")
 {
   GIVEN("A string")