kstd: ring_buffer: implement copy ctor

2 files changed, 36 insertions, 0 deletions

diff --git a/libs/kstd/kstd/ring_buffer.hpp b/libs/kstd/kstd/ring_buffer.hpp
index aa0b3a5c..2b97e0a9 100644
--- a/libs/kstd/kstd/ring_buffer.hpp
+++ b/libs/kstd/kstd/ring_buffer.hpp
@@ -175,6 +175,15 @@ namespace kstd
     //! Construct an empty ring buffer.
     constexpr ring_buffer() noexcept = default;
 
+    //! Construct a ring buffer by copying from an existing one.
+    constexpr ring_buffer(ring_buffer const & other)
+        : m_size{other.m_size}
+        , m_read_index{}
+    {
+      std::ranges::for_each(std::views::iota(0uz, other.size()),
+                            [&](auto const i) { m_storage.construct(i, other[i]); });
+    }
+
     //! Destroy this ring buffer.
     constexpr ~ring_buffer() noexcept
     {
diff --git a/libs/kstd/kstd/ring_buffer.tests.cpp b/libs/kstd/kstd/ring_buffer.tests.cpp
index 2a2d23b0..4e34249b 100644
--- a/libs/kstd/kstd/ring_buffer.tests.cpp
+++ b/libs/kstd/kstd/ring_buffer.tests.cpp
@@ -6,9 +6,12 @@
 #include <catch2/matchers/catch_matchers.hpp>
 #include <catch2/matchers/catch_matchers_exception.hpp>
 
+#include <algorithm>
 #include <cstddef>
+#include <functional>
 #include <iterator>
 #include <memory>
+#include <string>
 #include <type_traits>
 #include <utility>
 
@@ -303,6 +306,30 @@ SCENARIO("Ring Buffer initialization and construction", "[kstd][ring_buffer]")
       REQUIRE(buffer.size() == buffer.capacity());
     }
   }
+
+  GIVEN("A buffer with a capacity of 5 containing 3 elements")
+  {
+    auto buffer = kstd::ring_buffer<std::string, 5>{3, "test"};
+
+    WHEN("constructing a copy")
+    {
+      auto copy = buffer;
+
+      THEN("the contents of both are identical")
+      {
+        REQUIRE(std::ranges::equal(buffer, copy));
+      }
+
+      THEN("their element addresses differ")
+      {
+        auto address_of = [](auto const & obj) {
+          return std::addressof(obj);
+        };
+
+        REQUIRE_FALSE(std::ranges::equal(buffer, copy, std::equal_to{}, address_of, address_of));
+      }
+    }
+  }
 }
 
 SCENARIO("Ring Buffer destruction", "[kstd][ring_buffer]")