Merge pull request #6 from KredeGC/hotfix

Fix unspecified behaviour in linear and stack allocators

include/ktl/allocators/linear_allocator.h

@@ -127,7 +127,13 @@ namespace ktl
 		*/
 		bool owns(void* p) const noexcept
 		{
-			return p >= m_Data && p < m_Data + Size;
+			// Comparing pointers to different objects is unspecified
+			// But converting them to integers and comparing them isn't...
+			uintptr_t ptr = reinterpret_cast<uintptr_t>(p);
+			uintptr_t low = reinterpret_cast<uintptr_t>(m_Data);
+			uintptr_t high = low + Size;
+
+			return ptr >= low && ptr < high;
 		}
 #pragma endregion
 

include/ktl/allocators/stack_allocator.h

@@ -98,7 +98,13 @@ namespace ktl
 
 		bool owns(void* p) const noexcept
 		{
-			return p >= m_Block->Data && p < m_Block->Data + Size;
+			// Comparing pointers to different objects is unspecified
+			// But converting them to integers and comparing them isn't...
+			uintptr_t ptr = reinterpret_cast<uintptr_t>(p);
+			uintptr_t low = reinterpret_cast<uintptr_t>(m_Block->Data);
+			uintptr_t high = low + Size;
+
+			return ptr >= low && ptr < high;
 		}
 #pragma endregion
 

include/ktl/allocators/type_allocator.h

@@ -21,6 +21,10 @@ namespace ktl
 	private:
 		static_assert(detail::has_no_value_type_v<Alloc>, "Building on top of typed allocators is not allowed. Use allocators without a type");
 		static_assert(!std::is_const_v<T>, "Using an allocator of const T is ill-formed");
+		static_assert(!std::is_copy_constructible_v<Alloc> || std::is_nothrow_copy_constructible_v<Alloc>, "Using a throwing copy constructor is ill-formed");
+		static_assert(!std::is_move_constructible_v<Alloc> || std::is_nothrow_move_constructible_v<Alloc>, "Using a throwing move constructor is ill-formed");
+		static_assert(!std::is_copy_assignable_v<Alloc> || std::is_nothrow_copy_assignable_v<Alloc>, "Using throwing copy assignment is ill-formed");
+		static_assert(!std::is_move_assignable_v<Alloc> || std::is_nothrow_move_assignable_v<Alloc>, "Using throwing move assignment is ill-formed");
 
 		template<typename U, typename A>
 		friend class type_allocator;
@@ -54,21 +58,36 @@ namespace ktl
 
 		type_allocator(const type_allocator&) = default;
 
-		type_allocator(type_allocator&&) = default;
+		// Move construction is essentially forbidden for STL allocators
+		// A al(std::move(a)); a == al
+		// https://en.cppreference.com/w/cpp/named_req/Allocator
+		type_allocator(type_allocator&& other)
+			noexcept(std::is_nothrow_copy_constructible_v<Alloc>) :
+			m_Alloc(other.m_Alloc) {}
 
 		template<typename U>
 		type_allocator(const type_allocator<U, Alloc>& other)
 			noexcept(std::is_nothrow_constructible_v<Alloc, const type_allocator<U, Alloc>&>) :
 			m_Alloc(other.m_Alloc) {}
 
+		// Move construction is essentially forbidden for STL allocators
+		// https://en.cppreference.com/w/cpp/named_req/Allocator
 		template<typename U>
 		type_allocator(type_allocator<U, Alloc>&& other)
 			noexcept(std::is_nothrow_constructible_v<Alloc, type_allocator<U, Alloc>&&>) :
-			m_Alloc(std::move(other.m_Alloc)) {}
+			m_Alloc(other.m_Alloc) {}
 
 		type_allocator& operator=(const type_allocator&) = default;
 
-		type_allocator& operator=(type_allocator&&) = default;
+		// Move construction is essentially forbidden for STL allocators
+		// https://en.cppreference.com/w/cpp/named_req/Allocator
+		type_allocator& operator=(type_allocator&& rhs)
+			noexcept(std::is_nothrow_copy_assignable_v<Alloc>)
+		{
+			m_Alloc = rhs.m_Alloc;
+
+			return *this;
+		}
 
 #pragma region Allocation
 		/**

include/ktl/containers/trivial_vector.h

@@ -338,7 +338,7 @@ namespace ktl
 		{
 			const size_t n = (last - first);
 
-			if (m_EndMax - m_End < n)
+			if (size_t(m_EndMax - m_End) < n)
 				expand(n);
 
 			T* lastElement = m_End;

src/test/exotic_allocator_test.cpp

@@ -25,9 +25,9 @@ namespace ktl::test::exotic_allocator
     {
         // TODO: More tests with exotic allocator arrangements
         stack<1024> block;
-        type_segragator_allocator<double, 32, stack_allocator<1024>, cascading<linear_allocator<1024>>> alloc(block);
+        segragator<32, stack_allocator<1024>, cascading<linear_allocator<1024>>> alloc(block);
 
-        type_segragator_allocator<double, 32, stack_allocator<1024>, cascading<linear_allocator<1024>>> alloc2(std::move(alloc));
+        segragator<32, stack_allocator<1024>, cascading<linear_allocator<1024>>> alloc2(std::move(alloc));
     }
 
     KTL_ADD_TEST(test_exotic_allocator_1)