101 lines
3.1 KiB
C++
101 lines
3.1 KiB
C++
/**
|
|
This file is a part of rexy's general purpose library
|
|
Copyright (C) 2022 rexy712
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef REXY_COMPAT_CPP17_DEFAULT_ALLOCATOR_HPP
|
|
#define REXY_COMPAT_CPP17_DEFAULT_ALLOCATOR_HPP
|
|
|
|
#include <cstddef> //ptrdiff_t, size_t
|
|
#include <type_traits> //true_type, false_type
|
|
#include <new>
|
|
#include <limits> //numeric_limits
|
|
|
|
#include "../../rexy.hpp"
|
|
|
|
#define REXY_ALLOCATOR_CONCEPT class
|
|
|
|
namespace rexy{
|
|
|
|
template<class T>
|
|
struct allocator
|
|
{
|
|
using pointer = T*;
|
|
using const_pointer = const T*;
|
|
using void_pointer = void*;
|
|
using const_void_pointer = const void*;
|
|
using value_type = T;
|
|
using size_type = std::size_t;
|
|
using difference_type = ptrdiff_t;
|
|
using is_always_equal = std::true_type;
|
|
using propagate_on_container_copy_assignment = std::false_type;
|
|
using propagate_on_container_move_assignment = std::false_type;
|
|
using propagate_on_container_swap = std::false_type;
|
|
|
|
template<class U>
|
|
struct rebind{
|
|
using other = allocator<U>;
|
|
};
|
|
|
|
private:
|
|
constexpr bool has_overflow(size_type n)const{
|
|
return n > max_size();
|
|
}
|
|
|
|
public:
|
|
allocator(void) = default;
|
|
allocator(const allocator&) = default;
|
|
allocator(allocator&&) = default;
|
|
template<class U>
|
|
constexpr allocator(const allocator<U>&)noexcept{}
|
|
~allocator(void) = default;
|
|
|
|
pointer allocate(size_type n){
|
|
size_type bytes = has_overflow(n) ? std::numeric_limits<size_type>::max() : n*sizeof(T);
|
|
|
|
if constexpr(alignof(T) <= __STDCPP_DEFAULT_NEW_ALIGNMENT__){
|
|
return reinterpret_cast<pointer>(::operator new(bytes));
|
|
}else{
|
|
return reinterpret_cast<pointer>(::operator new(bytes, static_cast<std::align_val_t>(alignof(T))));
|
|
}
|
|
}
|
|
void deallocate(pointer p, size_type n){
|
|
#if !defined(__cpp_sized_deallocation)
|
|
//clang does not enable ::operator delete(void* ptr, std::size_t sz) by default for some reason
|
|
if constexpr(alignof(T) <= __STDCPP_DEFAULT_NEW_ALIGNMENT__){
|
|
::operator delete(p);
|
|
}else{
|
|
::operator delete(p, static_cast<std::align_val_t>(alignof(T)));
|
|
}
|
|
#else //__cpp_sized_deallocation
|
|
size_type bytes = has_overflow(n) ? std::numeric_limits<size_type>::max() : n*sizeof(T);
|
|
if constexpr(alignof(T) <= __STDCPP_DEFAULT_NEW_ALIGNMENT__){
|
|
::operator delete(p, bytes);
|
|
}else{
|
|
::operator delete(p, bytes, static_cast<std::align_val_t>(alignof(T)));
|
|
}
|
|
#endif //__cpp_sized_deallocation
|
|
|
|
}
|
|
constexpr size_type max_size(void)const{
|
|
return std::numeric_limits<size_type>::max()/sizeof(T);
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|