C语言库函数的原型,有用的拿去

				/***
				*memcpy.c - contains memcpy routine
				*
				*       Copyright (c) Microsoft Corporation. All rights reserved.
				*
				*Purpose:
				*       memcpy() copies a source memory buffer to a destination buffer.
				*       Overlapping buffers are not treated specially, so propogation may occur.
				*
				*******************************************************************************/
				
				#include 
				#include 
				
				#pragma function(memcpy)
				
				/***
				*memcpy - Copy source buffer to destination buffer
				*
				*Purpose:
				*       memcpy() copies a source memory buffer to a destination memory buffer.
				*       This routine does NOT recognize overlapping buffers, and thus can lead
				*       to propogation.
				*
				*       For cases where propogation must be avoided, memmove() must be used.
				*
				*Entry:
				*       void *dst = pointer to destination buffer
				*       const void *src = pointer to source buffer
				*       size_t count = number of bytes to copy
				*
				*Exit:
				*       Returns a pointer to the destination buffer
				*
				*Exceptions:
				*******************************************************************************/
				
				void * __cdecl memcpy (
				        void * dst,
				        const void * src,
				        size_t count
				        )
				{
				        void * ret = dst;
				
				#if defined (_M_IA64)
				
				        {
				
				
				        __declspec(dllimport)
				
				
				        void RtlCopyMemory( void *, const void *, size_t count );
				
				        RtlCopyMemory( dst, src, count );
				
				        }
				
				#else  /* defined (_M_IA64) */
				        /*
				         * copy from lower addresses to higher addresses
				         */
				        while (count--) {
				                *(char *)dst = *(char *)src;
				                dst = (char *)dst + 1;
				                src = (char *)src + 1;
				        }
				#endif  /* defined (_M_IA64) */
				
				        return(ret);
				}