#ifndef KSTD_ALLOCATOR_H_
#define KSTD_ALLOCATOR_H_// 這個頭文件包含一個模板類 allocator，用于管理內存的分配、釋放，對象的構造、析構
// 暫不支持標準庫容器 todo::支持萃取#include <new>      // placement new
#include <cstddef>  // ptrdiff_t size_t
#include <cstdlib>  // exit
#include <climits>  // UINT_MAX
#include <iostream> // cerrnamespace kstd
{/*new 處理函數set_new_handler()是為分配函數在凡是內存分配嘗試失敗時調用的函數。其目的是三件事之一：1) 令更多內存可用2) 終止程序（例如通過調用 std::terminate3) 拋出 std::bad_alloc 或自 std::bad_alloc 導出的類型的異常。*///創建內存template <class T>inline T *_allocate(ptrdiff_t size, T *){// set_new_handler(0);// there are no arguments to ‘set_new_handler’// that depend on a template parameter, so a declaration of//‘set_new_handler’ must be available [-fpermissive]T *tmp = (T *)(::operator new((size_t)(size * sizeof(T))));if (!tmp){std::cerr << "out of memory" << std::endl;exit(1);}return tmp;}//銷毀內存template <class T>inline void _deallocate(T *buffer){::operator delete(buffer);}//構造函數 placement newtemplate <class T1, class T2>inline void _construct(T1 *p, const T2 &value){new (p) T1(value);}template <class T>inline void _construct(T* ptr){new (ptr) T;}//析構template <class T>inline void _destroy(T *ptr){ptr->~T();}// 模板類：allocator// 模板函數代表數據類型template <class T>class allocator{public:typedef T value_type;typedef T *pointer;typedef const T *const_pointer;typedef T &reference;typedef const T &const_reference;typedef size_t size_type;typedef ptrdiff_t difference_type;public:static pointer allocate(size_type n, const void *hint = 0){return _allocate((difference_type)n, (pointer)0);}static void deallocate(pointer ptr);static void construct(pointer ptr, const_reference value);static void construct(pointer ptr);static void destroy(pointer ptr);};template <class T>void allocator<T>::deallocate(pointer ptr){_deallocate(ptr);}template <class T>void allocator<T>::construct(pointer ptr, const_reference value){_construct(ptr, value);}template <class T>void allocator<T>::construct(pointer ptr){_construct(ptr);}template <class T>void allocator<T>::destroy(pointer ptr){_destroy(ptr);}} // namespace kstd
#endif // KSTD_ALLOCATOR_H_