jjalloc.h

代码中包含了部分作者侯捷的<<STL源码剖析>>一书中的程序实例,有助于理解及应用STL,来进行方便高效的编程

#ifndef _JJALLOC_
#define _JJALLOC_

#include <new>
#include <cstddef>
#include <cstdlib>
#include <climits>
#include <iostream>

namespace JJ
{
	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);
	}
	template <class T1,class T2>
		inline void _construct(T1* p,const T2& value)
	{
		new(p) T1(value);
	}
	template <class T>
		inline void _destroy(T* ptr)
	{
		ptr->~T();
	}
	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;

			template <class U>
				struct rebind
			{
				typedef allocator<U> other;
			};
			pointer allocate(size_type n,const void* hint=0)
			{
				return _allocate((difference->type)n,(pointer)0);
			}
			void deallocate(pointer p,size_type n)
			{
				_deallocate(p);
			}
			void construct(pointer p,const T& valude)
			{
				_construct(p,value);
			}
			void destroy(pointer p)
			{
				_destroy(p);
			}
			pointer address(reference x)
			{
				return (pointer) &x;
			}
			const_pointer const_address(const_reference x)
			{
				return (const_pointer)&x;
			}
			size_type max_size()const
			{
				return size_type(UINT_MAX/sizeof(T));
			}
	};
}
#endif