// Filename: defalloc.h
// Comment By: 凝霜
// E-mail: mdl2009@vip.qq.com
// Blog: http://blog.csdn.net/mdl13412
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*/
// 這個檔案提供原始的HP預設allocator, 僅僅是為了向後相容
//
// 不要使用這個檔案,除非你使用一個需要HP-style allocator的舊容器
// SGI STL使用一個不同的allocator介面
// SGI-style的allocator不針對物件型別進行引數化, 他使用void *指標
#ifndef DEFALLOC_H
#define DEFALLOC_H
#include <new.h>
#include <stddef.h>
#include <stdlib.h>
#include <limits.h>
#include <iostream.h>
#include <algobase.h>
// 如果記憶體分配失敗, 則直接退出程式
template <class T>
inline T* allocate(ptrdiff_t size, T*)
{
set_new_handler(0);
T* tmp = (T*)(::operator new((size_t)(size * sizeof(T))));
if (tmp == 0) {
cerr << "out of memory" << endl;
exit(1);
}
return tmp;
}
template <class T>
inline void deallocate(T* buffer)
{
::operator delete(buffer);
}
// 標準的STL allocator介面
template <class T>
class allocator
{
public:
// STL type_traits需要的標準定義
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;
pointer allocate(size_type n)
{
return ::allocate((difference_type)n, (pointer)0);
}
void deallocate(pointer p) { ::deallocate(p); }
pointer address(reference x) { return (pointer)&x; }
const_pointer const_address(const_reference x)
{
return (const_pointer)&x;
}
//
size_type init_page_size()
{
return max(size_type(1), size_type(4096/sizeof(T)));
}
size_type max_size() const
{
return max(size_type(1), size_type(UINT_MAX/sizeof(T)));
}
};
// 僅使用void *型別的指標
class allocator<void>
{
public:
typedef void* pointer;
};
#endif