24 Strings library [strings]

24.5 Null-terminated sequence utilities [c.strings]

24.5.3 Header <cstring> synopsis [cstring.syn]

namespace std {
  using size_t = see [support.types.layout];

  void* memcpy(void* s1, const void* s2, size_t n);
  void* memmove(void* s1, const void* s2, size_t n);
  char* strcpy(char* s1, const char* s2);
  char* strncpy(char* s1, const char* s2, size_t n);
  char* strcat(char* s1, const char* s2);
  char* strncat(char* s1, const char* s2, size_t n);
  int memcmp(const void* s1, const void* s2, size_t n);
  int strcmp(const char* s1, const char* s2);
  int strcoll(const char* s1, const char* s2);
  int strncmp(const char* s1, const char* s2, size_t n);
  size_t strxfrm(char* s1, const char* s2, size_t n);
  const void* memchr(const void* s, int c, size_t n);  // see [library.c]
  void* memchr(void* s, int c, size_t n);  // see [library.c]
  const char* strchr(const char* s, int c);  // see [library.c]
  char* strchr(char* s, int c);  // see [library.c]
  size_t strcspn(const char* s1, const char* s2);
  const char* strpbrk(const char* s1, const char* s2);  // see [library.c]
  char* strpbrk(char* s1, const char* s2);  // see [library.c]
  const char* strrchr(const char* s, int c);  // see [library.c]
  char* strrchr(char* s, int c);  // see [library.c]
  size_t strspn(const char* s1, const char* s2);
  const char* strstr(const char* s1, const char* s2);  // see [library.c]
  char* strstr(char* s1, const char* s2);  // see [library.c]
  char* strtok(char* s1, const char* s2);
  void* memset(void* s, int c, size_t n);
  char* strerror(int errnum);
  size_t strlen(const char* s);
}

#define NULL see [support.types.nullptr]
The contents and meaning of the header <cstring> are the same as the C standard library header <string.h>.
The functions strerror and strtok are not required to avoid data races.
The functions memcpy and memmove are signal-safe.
[Note
:
The functions strchr, strpbrk, strrchr, strstr, and memchr, have different signatures in this International Standard, but they have the same behavior as in the C standard library.
end note
]
See also: ISO C 7.
24