From a958c515e4cfcd5572ac7e2c3a567e832630a12d Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Fri, 1 May 2026 11:34:54 +0200
Subject: kstd/vector: implement append_range

---
 libs/kstd/include/kstd/bits/concepts.hpp | 15 +++++++
 libs/kstd/include/kstd/vector            | 69 +++++++++++++++++++++++++++++++-
 2 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 libs/kstd/include/kstd/bits/concepts.hpp

(limited to 'libs/kstd/include')

diff --git a/libs/kstd/include/kstd/bits/concepts.hpp b/libs/kstd/include/kstd/bits/concepts.hpp
new file mode 100644
index 0000000..74c25cb
--- /dev/null
+++ b/libs/kstd/include/kstd/bits/concepts.hpp
@@ -0,0 +1,15 @@
+#ifndef KSTD_BITS_CONCEPTS_HPP
+#define KSTD_BITS_CONCEPTS_HPP
+
+#include <concepts>
+#include <ranges>
+namespace kstd::bits
+{
+
+  template<typename RangeType, typename ValueType>
+  concept container_compatible_range =
+      std::ranges::input_range<RangeType> && std::convertible_to<std::ranges::range_reference_t<RangeType>, ValueType>;
+
+}
+
+#endif
diff --git a/libs/kstd/include/kstd/vector b/libs/kstd/include/kstd/vector
index 97fdffe..2ecb6a8 100644
--- a/libs/kstd/include/kstd/vector
+++ b/libs/kstd/include/kstd/vector
@@ -2,6 +2,7 @@
 #define KSTD_VECTOR_HPP
 
 #include <kstd/allocator>
+#include <kstd/bits/concepts.hpp>
 #include <kstd/os/error.hpp>
 #include <kstd/ranges>
 
@@ -882,6 +883,68 @@ namespace kstd
       return this->back();
     }
 
+    //! Append the elements of a given range to this vector.
+    //!
+    //! @param range The range of elements to be appended.
+    //! @tparam SourceRange A container compatible range type.
+    template<kstd::bits::container_compatible_range<ValueType> SourceRange>
+      requires requires(Allocator allocator, pointer destination, SourceRange range) {
+        std::allocator_traits<Allocator>::construct(allocator, destination, *std::ranges::begin(range));
+      }
+    // NOLINTNEXTLINE(cppcoreguidelines-missing-std-forward, misc-no-recursion)
+    constexpr auto append_range(SourceRange && range) -> void
+    {
+      if constexpr (std::ranges::forward_range<SourceRange> || std::ranges::sized_range<SourceRange>)
+      {
+        auto number_of_elements = static_cast<size_type>(std::ranges::distance(range));
+
+        if (!capacity())
+        {
+          reserve(number_of_elements);
+        }
+
+        if (capacity() - size() >= number_of_elements)
+        {
+          uninitialized_copy_with_allocator(std::ranges::begin(range), end(), number_of_elements);
+          m_size += number_of_elements;
+          return;
+        }
+
+        auto new_capacity = m_capacity + std::max(size(), number_of_elements);
+        auto new_data = allocate_n(new_capacity);
+        auto old_size = size();
+
+        uninitialized_move_with_allocator(begin(), new_data, size());
+        uninitialized_copy_with_allocator(std::ranges::begin(range), new_data + size(), number_of_elements);
+        clear_and_deallocate();
+        m_data = new_data;
+        m_capacity = new_capacity;
+        m_size = old_size + number_of_elements;
+        return;
+      }
+
+      auto range_begin = std::ranges::begin(range);
+      auto range_end = std::ranges::end(range);
+
+      for (auto i = capacity() - size(); i > 0; --i, ++range_begin)
+      {
+        emplace_back(*range_begin);
+      }
+
+      if (range_begin == range_end)
+      {
+        return;
+      }
+
+      auto remainder = vector{get_allocator()};
+      for (; range_begin != range_end; ++range_begin)
+      {
+        remainder.emplace_back(*static_cast<std::ranges::iterator_t<SourceRange>>(range_begin));
+      }
+      reserve(size() + std::max(size(), remainder.size()));
+      append_range(remainder);
+    }
+
     //! Remove the last element of this vector.
     //!
     //! If this vector is empty, the behavior is undefined.
@@ -950,7 +1013,8 @@ namespace kstd
     //! @param from The start of the source range.
     //! @param to The start of the target range inside this vector.
     //! @param count The number of elements to copy
-    constexpr auto uninitialized_copy_with_allocator(const_iterator from, iterator to, size_type count)
+    template<typename SourceIterator>
+    constexpr auto uninitialized_copy_with_allocator(SourceIterator from, iterator to, size_type count)
     {
       for (auto i = 0uz; i < count; ++i)
       {
@@ -963,7 +1027,8 @@ namespace kstd
     //! @param from The start of the source range.
     //! @param to The start of the target range inside this vector.
     //! @param count The number of elements to copy
-    constexpr auto uninitialized_move_with_allocator(iterator from, iterator to, size_type count)
+    template<typename SourceIterator>
+    constexpr auto uninitialized_move_with_allocator(SourceIterator from, iterator to, size_type count)
     {
       for (auto i = 0uz; i < count; ++i)
       {
-- 
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