kstd/vector: implement range erase

2 files changed, 82 insertions, 0 deletions

diff --git a/libs/kstd/include/kstd/vector b/libs/kstd/include/kstd/vector
index 771fc87..9e41cb6 100644
--- a/libs/kstd/include/kstd/vector
+++ b/libs/kstd/include/kstd/vector
@@ -711,6 +711,28 @@ namespace kstd
       return begin() + prefix_size;
     }
 
+    //! Erase a range of elements from this vector.
+    //!
+    //! @param first The start of the range to erase.
+    //! @param last The end of the range to erase.
+    //! @return An iterator pointing to the element after the last deleted element.
+    constexpr auto erase(const_iterator first, const_iterator last) -> iterator
+    {
+      if (first == last)
+      {
+        return begin() + std::ranges::distance(cbegin(), first);
+      }
+
+      auto prefix_size = std::ranges::distance(cbegin(), first);
+      auto element_count = std::ranges::distance(first, last);
+
+      std::ranges::move(begin() + prefix_size + element_count, end(), begin() + prefix_size);
+      destroy_n(end() - element_count, element_count);
+      m_size -= element_count;
+
+      return begin() + prefix_size;
+    }
+
     //! Append a given element to this vector via copy construction.
     constexpr auto push_back(value_type const & value) -> void
     {
diff --git a/libs/kstd/tests/src/vector.cpp b/libs/kstd/tests/src/vector.cpp
index 913427c..b7971f4 100644
--- a/libs/kstd/tests/src/vector.cpp
+++ b/libs/kstd/tests/src/vector.cpp
@@ -760,6 +760,33 @@ SCENARIO("Vector modifiers", "[vector]")
         REQUIRE_THROWS_AS(v.erase(v.end()), kstd::tests::os_panic);
       }
     }
+
+    WHEN("erasing a range of elements")
+    {
+      auto it = v.erase(v.cbegin() + 1, v.cend() - 1);
+
+      THEN("the specified range is removed and the size decreases")
+      {
+        REQUIRE(v.size() == 2);
+        REQUIRE(v[0] == 10);
+        REQUIRE(v[1] == 30);
+        REQUIRE(it == v.begin() + 1);
+      }
+    }
+
+    WHEN("erasing an empty range")
+    {
+      auto it = v.erase(v.cbegin() + 1, v.cbegin() + 1);
+
+      THEN("the vector is unchanged")
+      {
+        REQUIRE(v.size() == 3);
+        REQUIRE(v[0] == 10);
+        REQUIRE(v[1] == 20);
+        REQUIRE(v[2] == 30);
+        REQUIRE(it == v.begin() + 1);
+      }
+    }
   }
 }
 
@@ -1031,6 +1058,39 @@ SCENARIO("Vector modifier move semantics", "[vector]")
         REQUIRE(it == v.end());
       }
     }
+
+    WHEN("erasing a range of elements in the middle")
+    {
+      v.emplace_back(40);
+      v.emplace_back(50);
+
+      for (auto & elem : v)
+      {
+        elem.was_copied = false;
+        elem.was_moved = false;
+      }
+
+      auto it = v.erase(v.cbegin() + 1, v.cbegin() + 3);
+
+      THEN("the specified elements are destroyed and subsequent elements are move-assigned leftwards")
+      {
+        REQUIRE(v.size() == 3);
+
+        REQUIRE(v[0].value == 10);
+        REQUIRE_FALSE(v[0].was_moved);
+        REQUIRE_FALSE(v[0].was_copied);
+
+        REQUIRE(v[1].value == 40);
+        REQUIRE(v[1].was_moved);
+        REQUIRE_FALSE(v[1].was_copied);
+
+        REQUIRE(v[2].value == 50);
+        REQUIRE(v[2].was_moved);
+        REQUIRE_FALSE(v[2].was_copied);
+
+        REQUIRE(it == v.begin() + 1);
+      }
+    }
   }
 }