c语言头文件cstring,头文件 <string.h> <cstring> <string> 区别

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发布于 2022-10-01 16:47:24

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/** @file cstring

* This is a Standard C++ Library file. You should @c \#include this file

* in your programs, rather than any of the @a *.h implementation files.

* This is the C++ version of the Standard C Library header @c string.h,

* and its contents are (mostly) the same as that header, but are all

* contained in the namespace @c std (except for names which are defined

* as macros in C).*/

//ISO C++ 14882: 20.4.6 C library//

#pragma GCC system_header#include#include#ifndef _GLIBCXX_CSTRING#define _GLIBCXX_CSTRING 1

//Get rid of those macros defined in in lieu of real functions.

#undef memchr

#undef memcmp

#undef memcpy

#undef memmove

#undef memset

#undef strcat

#undef strchr

#undef strcmp

#undef strcoll

#undef strcpy

#undef strcspn

#undef strerror

#undef strlen

#undef strncat

#undef strncmp

#undef strncpy

#undef strpbrk

#undef strrchr

#undef strspn

#undef strstr

#undef strtok

#undef strxfrm

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_VERSIONusing::memchr;using::memcmp;using::memcpy;using::memmove;using::memset;using::strcat;using::strcmp;using::strcoll;using::strcpy;using::strcspn;using::strerror;using::strlen;using::strncat;using::strncmp;using::strncpy;using::strspn;using::strtok;using::strxfrm;using::strchr;using::strpbrk;using::strrchr;using::strstr;

#ifndef __CORRECT_ISO_CPP_STRING_H_PROTO

inlinevoid*memchr(void* __s, int__c, size_t __n)

{return__builtin_memchr(__s, __c, __n); }

inlinechar*strchr(char* __s, int__n)

{return__builtin_strchr(__s, __n); }

inlinechar*strpbrk(char* __s1, const char*__s2)

{return__builtin_strpbrk(__s1, __s2); }

inlinechar*strrchr(char* __s, int__n)

{return__builtin_strrchr(__s, __n); }

inlinechar*strstr(char* __s1, const char*__s2)

{return__builtin_strstr(__s1, __s2); }#endif_GLIBCXX_END_NAMESPACE_VERSION

}//namespace