From 3bf42c6ff3805a0d42bbc661794a95ff31bedc26 Mon Sep 17 00:00:00 2001 From: untodesu Date: Sat, 15 Mar 2025 16:22:09 +0500 Subject: Add whatever I was working on for the last month --- deps/include/entt/core/memory.hpp | 244 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 244 insertions(+) create mode 100644 deps/include/entt/core/memory.hpp (limited to 'deps/include/entt/core/memory.hpp') diff --git a/deps/include/entt/core/memory.hpp b/deps/include/entt/core/memory.hpp new file mode 100644 index 0000000..58fda45 --- /dev/null +++ b/deps/include/entt/core/memory.hpp @@ -0,0 +1,244 @@ +#ifndef ENTT_CORE_MEMORY_HPP +#define ENTT_CORE_MEMORY_HPP + +#include +#include +#include +#include +#include +#include "../config/config.h" + +namespace entt { + +/** + * @brief Unwraps fancy pointers, does nothing otherwise (waiting for C++20). + * @tparam Type Pointer type. + * @param ptr Fancy or raw pointer. + * @return A raw pointer that represents the address of the original pointer. + */ +template +[[nodiscard]] constexpr auto to_address(Type &&ptr) noexcept { + if constexpr(std::is_pointer_v>) { + return ptr; + } else { + return to_address(std::forward(ptr).operator->()); + } +} + +/** + * @brief Utility function to design allocation-aware containers. + * @tparam Allocator Type of allocator. + * @param lhs A valid allocator. + * @param rhs Another valid allocator. + */ +template +constexpr void propagate_on_container_copy_assignment([[maybe_unused]] Allocator &lhs, [[maybe_unused]] Allocator &rhs) noexcept { + if constexpr(std::allocator_traits::propagate_on_container_copy_assignment::value) { + lhs = rhs; + } +} + +/** + * @brief Utility function to design allocation-aware containers. + * @tparam Allocator Type of allocator. + * @param lhs A valid allocator. + * @param rhs Another valid allocator. + */ +template +constexpr void propagate_on_container_move_assignment([[maybe_unused]] Allocator &lhs, [[maybe_unused]] Allocator &rhs) noexcept { + if constexpr(std::allocator_traits::propagate_on_container_move_assignment::value) { + lhs = std::move(rhs); + } +} + +/** + * @brief Utility function to design allocation-aware containers. + * @tparam Allocator Type of allocator. + * @param lhs A valid allocator. + * @param rhs Another valid allocator. + */ +template +constexpr void propagate_on_container_swap([[maybe_unused]] Allocator &lhs, [[maybe_unused]] Allocator &rhs) noexcept { + if constexpr(std::allocator_traits::propagate_on_container_swap::value) { + using std::swap; + swap(lhs, rhs); + } else { + ENTT_ASSERT_CONSTEXPR(lhs == rhs, "Cannot swap the containers"); + } +} + +/** + * @brief Deleter for allocator-aware unique pointers (waiting for C++20). + * @tparam Allocator Type of allocator used to manage memory and elements. + */ +template +struct allocation_deleter: private Allocator { + /*! @brief Allocator type. */ + using allocator_type = Allocator; + /*! @brief Pointer type. */ + using pointer = typename std::allocator_traits::pointer; + + /** + * @brief Inherited constructors. + * @param alloc The allocator to use. + */ + constexpr allocation_deleter(const allocator_type &alloc) noexcept(std::is_nothrow_copy_constructible_v) + : Allocator{alloc} {} + + /** + * @brief Destroys the pointed object and deallocates its memory. + * @param ptr A valid pointer to an object of the given type. + */ + constexpr void operator()(pointer ptr) noexcept(std::is_nothrow_destructible_v) { + using alloc_traits = std::allocator_traits; + alloc_traits::destroy(*this, to_address(ptr)); + alloc_traits::deallocate(*this, ptr, 1u); + } +}; + +/** + * @brief Allows `std::unique_ptr` to use allocators (waiting for C++20). + * @tparam Type Type of object to allocate for and to construct. + * @tparam Allocator Type of allocator used to manage memory and elements. + * @tparam Args Types of arguments to use to construct the object. + * @param allocator The allocator to use. + * @param args Parameters to use to construct the object. + * @return A properly initialized unique pointer with a custom deleter. + */ +template +ENTT_CONSTEXPR auto allocate_unique(Allocator &allocator, Args &&...args) { + static_assert(!std::is_array_v, "Array types are not supported"); + + using alloc_traits = typename std::allocator_traits::template rebind_traits; + using allocator_type = typename alloc_traits::allocator_type; + + allocator_type alloc{allocator}; + auto ptr = alloc_traits::allocate(alloc, 1u); + + ENTT_TRY { + alloc_traits::construct(alloc, to_address(ptr), std::forward(args)...); + } + ENTT_CATCH { + alloc_traits::deallocate(alloc, ptr, 1u); + ENTT_THROW; + } + + return std::unique_ptr>{ptr, alloc}; +} + +/*! @cond TURN_OFF_DOXYGEN */ +namespace internal { + +template +struct uses_allocator_construction { + template + static constexpr auto args([[maybe_unused]] const Allocator &allocator, Params &&...params) noexcept { + if constexpr(!std::uses_allocator_v && std::is_constructible_v) { + return std::forward_as_tuple(std::forward(params)...); + } else { + static_assert(std::uses_allocator_v, "Ill-formed request"); + + if constexpr(std::is_constructible_v) { + return std::tuple{std::allocator_arg, allocator, std::forward(params)...}; + } else { + static_assert(std::is_constructible_v, "Ill-formed request"); + return std::forward_as_tuple(std::forward(params)..., allocator); + } + } + } +}; + +template +struct uses_allocator_construction> { + using type = std::pair; + + template + static constexpr auto args(const Allocator &allocator, std::piecewise_construct_t, First &&first, Second &&second) noexcept { + return std::make_tuple( + std::piecewise_construct, + std::apply([&allocator](auto &&...curr) { return uses_allocator_construction::args(allocator, std::forward(curr)...); }, std::forward(first)), + std::apply([&allocator](auto &&...curr) { return uses_allocator_construction::args(allocator, std::forward(curr)...); }, std::forward(second))); + } + + template + static constexpr auto args(const Allocator &allocator) noexcept { + return uses_allocator_construction::args(allocator, std::piecewise_construct, std::tuple<>{}, std::tuple<>{}); + } + + template + static constexpr auto args(const Allocator &allocator, First &&first, Second &&second) noexcept { + return uses_allocator_construction::args(allocator, std::piecewise_construct, std::forward_as_tuple(std::forward(first)), std::forward_as_tuple(std::forward(second))); + } + + template + static constexpr auto args(const Allocator &allocator, const std::pair &value) noexcept { + return uses_allocator_construction::args(allocator, std::piecewise_construct, std::forward_as_tuple(value.first), std::forward_as_tuple(value.second)); + } + + template + static constexpr auto args(const Allocator &allocator, std::pair &&value) noexcept { + return uses_allocator_construction::args(allocator, std::piecewise_construct, std::forward_as_tuple(std::move(value.first)), std::forward_as_tuple(std::move(value.second))); + } +}; + +} // namespace internal +/*! @endcond */ + +/** + * @brief Uses-allocator construction utility (waiting for C++20). + * + * Primarily intended for internal use. Prepares the argument list needed to + * create an object of a given type by means of uses-allocator construction. + * + * @tparam Type Type to return arguments for. + * @tparam Allocator Type of allocator used to manage memory and elements. + * @tparam Args Types of arguments to use to construct the object. + * @param allocator The allocator to use. + * @param args Parameters to use to construct the object. + * @return The arguments needed to create an object of the given type. + */ +template +constexpr auto uses_allocator_construction_args(const Allocator &allocator, Args &&...args) noexcept { + return internal::uses_allocator_construction::args(allocator, std::forward(args)...); +} + +/** + * @brief Uses-allocator construction utility (waiting for C++20). + * + * Primarily intended for internal use. Creates an object of a given type by + * means of uses-allocator construction. + * + * @tparam Type Type of object to create. + * @tparam Allocator Type of allocator used to manage memory and elements. + * @tparam Args Types of arguments to use to construct the object. + * @param allocator The allocator to use. + * @param args Parameters to use to construct the object. + * @return A newly created object of the given type. + */ +template +constexpr Type make_obj_using_allocator(const Allocator &allocator, Args &&...args) { + return std::make_from_tuple(internal::uses_allocator_construction::args(allocator, std::forward(args)...)); +} + +/** + * @brief Uses-allocator construction utility (waiting for C++20). + * + * Primarily intended for internal use. Creates an object of a given type by + * means of uses-allocator construction at an uninitialized memory location. + * + * @tparam Type Type of object to create. + * @tparam Allocator Type of allocator used to manage memory and elements. + * @tparam Args Types of arguments to use to construct the object. + * @param value Memory location in which to place the object. + * @param allocator The allocator to use. + * @param args Parameters to use to construct the object. + * @return A pointer to the newly created object of the given type. + */ +template +constexpr Type *uninitialized_construct_using_allocator(Type *value, const Allocator &allocator, Args &&...args) { + return std::apply([value](auto &&...curr) { return ::new(value) Type(std::forward(curr)...); }, internal::uses_allocator_construction::args(allocator, std::forward(args)...)); +} + +} // namespace entt + +#endif -- cgit