From a9f254dcea5cc73112ba4df96ceaf48a33fae216 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Thu, 2 Jan 2025 19:37:41 +0100
Subject: Implement copy move & assign for buffer

---
 asl/buffer.hpp             | 53 +++++++++++++++++++++++++++++++++++++---
 asl/memory.hpp             | 34 ++++++++++++++++++++++++++
 asl/tests/buffer_tests.cpp | 61 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 145 insertions(+), 3 deletions(-)

(limited to 'asl')

diff --git a/asl/buffer.hpp b/asl/buffer.hpp
index ca371d2..eab0a2e 100644
--- a/asl/buffer.hpp
+++ b/asl/buffer.hpp
@@ -5,6 +5,7 @@
 #include "asl/annotations.hpp"
 #include "asl/memory.hpp"
 #include "asl/assert.hpp"
+#include "asl/span.hpp"
 
 namespace asl
 {
@@ -141,7 +142,7 @@ private:
             isize_t other_n = other.size();
             isize_t this_n = size();
             resize_uninit(other_n);
-            if (other_n < this_n)
+            if (other_n <= this_n)
             {
                 relocate_assign_n(data(), other.data(), other_n);
             }
@@ -168,6 +169,26 @@ private:
         }
     }
 
+    void copy_range(span<const T> to_copy)
+    {
+        isize_t this_size = size();
+        isize_t new_size = to_copy.size();
+        
+        resize_uninit(to_copy.size());
+        ASL_ASSERT(capacity() >= new_size);
+        ASL_ASSERT(size() == to_copy.size());
+
+        if (new_size <= this_size)
+        {
+            copy_assign_n(data(), to_copy.data(), new_size);
+        }
+        else
+        {
+            copy_assign_n(data(), to_copy.data(), this_size);
+            copy_uninit_n(data() + this_size, to_copy.data() + this_size, new_size - this_size);
+        }
+    }
+
 public:
     constexpr buffer() requires default_constructible<Allocator> = default;
 
@@ -175,13 +196,30 @@ public:
         : m_allocator{ASL_MOVE(allocator)}
     {}
 
+    constexpr buffer(const buffer& other)
+        requires copy_constructible<Allocator> && copyable<T>
+        : m_allocator{other.m_allocator}
+    {
+        copy_range(other);
+    }
+
     constexpr buffer(buffer&& other)
+        requires moveable<T>
         : buffer(ASL_MOVE(other.m_allocator))
     {
         move_from_other(ASL_MOVE(other), false);
     }
+    
+    constexpr buffer& operator=(const buffer& other)
+        requires copyable<T>
+    {
+        if (&other == this) { return *this; }
+        copy_range(other);
+        return *this;
+    }
 
     constexpr buffer& operator=(buffer&& other)
+        requires moveable<T>
     {
         if (&other == this) { return *this; }
         move_from_other(ASL_MOVE(other), true);
@@ -193,8 +231,6 @@ public:
         destroy();
     }
 
-    // @Todo Copy constructor & assignment
-
     constexpr isize_t size() const
     {
         return decode_size(load_size_encoded());
@@ -307,6 +343,17 @@ public:
         }
     }
 
+    // @Todo(C++23) Deducing this
+    operator span<const T>() const // NOLINT(*-explicit-conversions)
+    {
+        return span<const T>{data(), size()};
+    }
+    
+    operator span<T>() // NOLINT(*-explicit-conversions)
+    {
+        return span<T>{data(), size()};
+    }
+
     // @Todo(C++23) Use deducing this
     constexpr T& operator[](isize_t i)
     {
diff --git a/asl/memory.hpp b/asl/memory.hpp
index 1209bf6..209f1d1 100644
--- a/asl/memory.hpp
+++ b/asl/memory.hpp
@@ -56,6 +56,40 @@ constexpr void destroy_n(T* data, isize_t n)
     }
 }
 
+template<copy_constructible T>
+constexpr void copy_uninit_n(T* to, const T* from, isize_t n)
+{
+    if constexpr (trivially_copy_constructible<T>)
+    {
+        memcpy(to, from, size_of<T> * n);
+    }
+    else
+    {
+        for (isize_t i = 0; i < n; ++i)
+        {
+            // NOLINTNEXTLINE(*-pointer-arithmetic)
+            construct_at<T>(to + i, from[i]);
+        }
+    }
+}
+
+template<copy_assignable T>
+constexpr void copy_assign_n(T* to, const T* from, isize_t n)
+{
+    if constexpr (trivially_copy_constructible<T>)
+    {
+        memcpy(to, from, size_of<T> * n);
+    }
+    else
+    {
+        for (isize_t i = 0; i < n; ++i)
+        {
+            // NOLINTNEXTLINE(*-pointer-arithmetic)
+            to[i] = from[i];
+        }
+    }
+}
+
 template<move_constructible T>
 constexpr void relocate_uninit_n(T* to, T* from, isize_t n)
 {
diff --git a/asl/tests/buffer_tests.cpp b/asl/tests/buffer_tests.cpp
index 1a08554..ad26c96 100644
--- a/asl/tests/buffer_tests.cpp
+++ b/asl/tests/buffer_tests.cpp
@@ -469,3 +469,64 @@ ASL_TEST(move_assign_from_inline_incompatible_allocator)
     ASL_TEST_EXPECT(d[4] == true);
     ASL_TEST_EXPECT(d[5] == true);
 }
+
+ASL_TEST(copy_construct_inline)
+{
+    asl::buffer<int> buf;
+    buf.push(0);
+    buf.push(1);
+    buf.push(2);
+
+    asl::buffer<int> buf2{buf};
+
+    ASL_TEST_EXPECT(buf.size() == buf2.size());
+    ASL_TEST_EXPECT(buf.size() == 3);
+    ASL_TEST_EXPECT(buf[0] == 0);
+    ASL_TEST_EXPECT(buf[1] == 1);
+    ASL_TEST_EXPECT(buf[2] == 2);
+    ASL_TEST_EXPECT(buf2[0] == 0);
+    ASL_TEST_EXPECT(buf2[1] == 1);
+    ASL_TEST_EXPECT(buf2[2] == 2);
+}
+
+ASL_TEST(copy_assign_into_smaller)
+{
+    asl::buffer<int> buf;
+    buf.push(0);
+    buf.push(1);
+    buf.push(2);
+
+    asl::buffer<int> buf2;
+    buf2.push(4);
+
+    buf2 = buf;
+
+    ASL_TEST_EXPECT(buf.size() == 3);
+    ASL_TEST_EXPECT(buf2.size() == 3);
+
+    ASL_TEST_EXPECT(buf[0] == 0);
+    ASL_TEST_EXPECT(buf[1] == 1);
+    ASL_TEST_EXPECT(buf[2] == 2);
+    ASL_TEST_EXPECT(buf2[0] == 0);
+    ASL_TEST_EXPECT(buf2[1] == 1);
+    ASL_TEST_EXPECT(buf2[2] == 2);
+}
+
+ASL_TEST(copy_assign_into_larger)
+{
+    asl::buffer<int> buf;
+    buf.push(0);
+    buf.push(1);
+    buf.push(2);
+
+    asl::buffer<int> buf2;
+    buf2.push(4);
+
+    buf = buf2;
+
+    ASL_TEST_EXPECT(buf.size() == 1);
+    ASL_TEST_EXPECT(buf2.size() == 1);
+
+    ASL_TEST_EXPECT(buf[0] == 4);
+    ASL_TEST_EXPECT(buf2[0] == 4);
+}
-- 
cgit