17 Language support library [support]

17.2 Common definitions [support.types]

17.2.2 Header <cstdlib> synopsis [cstdlib.syn]

namespace std { using size_t = see below; using div_t = see below; using ldiv_t = see below; using lldiv_t = see below; } #define NULL see below #define EXIT_FAILURE see below #define EXIT_SUCCESS see below #define RAND_MAX see below #define MB_CUR_MAX see below namespace std { // Exposition-only function type aliases extern "C" using c-atexit-handler = void(); // exposition only extern "C++" using atexit-handler = void(); // exposition only extern "C" using c-compare-pred = int(const void*, const void*); // exposition only extern "C++" using compare-pred = int(const void*, const void*); // exposition only // [support.start.term], start and termination [[noreturn]] void abort() noexcept; int atexit(c-atexit-handler* func) noexcept; int atexit(atexit-handler* func) noexcept; int at_quick_exit(c-atexit-handler* func) noexcept; int at_quick_exit(atexit-handler* func) noexcept; [[noreturn]] void exit(int status); [[noreturn]] void _Exit(int status) noexcept; [[noreturn]] void quick_exit(int status) noexcept; char* getenv(const char* name); int system(const char* string); // [c.malloc], C library memory allocation void* aligned_alloc(size_t alignment, size_t size); void* calloc(size_t nmemb, size_t size); void free(void* ptr); void* malloc(size_t size); void* realloc(void* ptr, size_t size); double atof(const char* nptr); int atoi(const char* nptr); long int atol(const char* nptr); long long int atoll(const char* nptr); double strtod(const char* nptr, char** endptr); float strtof(const char* nptr, char** endptr); long double strtold(const char* nptr, char** endptr); long int strtol(const char* nptr, char** endptr, int base); long long int strtoll(const char* nptr, char** endptr, int base); unsigned long int strtoul(const char* nptr, char** endptr, int base); unsigned long long int strtoull(const char* nptr, char** endptr, int base); // [c.mb.wcs], multibyte / wide string and character conversion functions int mblen(const char* s, size_t n); int mbtowc(wchar_t* pwc, const char* s, size_t n); int wctomb(char* s, wchar_t wchar); size_t mbstowcs(wchar_t* pwcs, const char* s, size_t n); size_t wcstombs(char* s, const wchar_t* pwcs, size_t n); // [alg.c.library], C standard library algorithms void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, c-compare-pred*[-1] compar); void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, compare-pred*[-1] compar); void qsort(void* base, size_t nmemb, size_t size, c-compare-pred*[-1] compar); void qsort(void* base, size_t nmemb, size_t size, compare-pred*[-1] compar); // [c.math.rand], low-quality random number generation int rand(); void srand(unsigned int seed); // [c.math.abs], absolute values int abs(int j); long int abs(long int j); long long int abs(long long int j); float abs(float j); double abs(double j); long double abs(long double j); long int labs(long int j); long long int llabs(long long int j); div_t div(int numer, int denom); ldiv_t div(long int numer, long int denom); // see [library.c] lldiv_t div(long long int numer, long long int denom); // see [library.c] ldiv_t ldiv(long int numer, long int denom); lldiv_t lldiv(long long int numer, long long int denom); }
The contents and meaning of the header <cstdlib> are the same as the C standard library header <stdlib.h>, except that it does not declare the type wchar_­t, and except as noted in [support.types.nullptr], [support.types.layout], [support.start.term], [c.malloc], [c.mb.wcs], [alg.c.library], [c.math.rand], and [c.math.abs].
[Note 1:
Several functions have additional overloads in this document, but they have the same behavior as in the C standard library.
— end note]
See also: ISO C 7.22