Standard library header <cstdlib>
From cppreference.com
This header was originally in the C standard library as <stdlib.h>.
This header provides miscellaneous utilities. Symbols defined here are used by several library components.
Macro constants
| indicates program execution execution status (macro constant) | |
| MB_CUR_MAX |
maximum number of bytes in a multibyte character with the current locale (macro constant) |
| implementation-defined null pointer constant (macro constant) | |
| maximum possible value generated by std::rand (macro constant) |
Types
| structure type, return of the std::div function (typedef) | |
| structure type, return of the std::ldiv function (typedef) | |
| (C++11) |
structure type, return of the std::lldiv function (typedef) |
| unsigned integer type returned by the sizeof operator (typedef) |
Functions
Process control | |
| causes abnormal program termination (without cleaning up) (function) | |
| causes normal program termination with cleaning up (function) | |
| (C++11) |
causes quick program termination without completely cleaning up (function) |
| (C++11) |
causes normal program termination without cleaning up (function) |
| registers a function to be called on std::exit() invocation (function) | |
| (C++11) |
registers a function to be called on quick_exit invocation (function) |
| calls the host environment's command processor (function) | |
| access to the list of environment variables (function) | |
Memory management | |
| allocates memory (function) | |
| (C++17) |
allocates aligned memory (function) |
| allocates and zeroes memory (function) | |
| expands previously allocated memory block (function) | |
| deallocates previously allocated memory (function) | |
Numeric string conversion | |
| converts a byte string to a floating point value (function) | |
| converts a byte string to an integer value (function) | |
| converts a byte string to an integer value (function) | |
| converts a byte string to an unsigned integer value (function) | |
| converts a byte string to a floating point value (function) | |
Wide string manipulation | |
| returns the number of bytes in the next multibyte character (function) | |
| converts the next multibyte character to wide character (function) | |
| converts a wide character to its multibyte representation (function) | |
| converts a narrow multibyte character string to wide string (function) | |
| converts a wide string to narrow multibyte character string (function) | |
Miscellaneous algorithms and math | |
| generates a pseudo-random number (function) | |
| seeds pseudo-random number generator (function) | |
| sorts a range of elements with unspecified type (function) | |
| searches an array for an element of unspecified type (function) | |
| (C++11) |
computes absolute value of an integral value (|x|) (function) |
| (C++11) |
computes quotient and remainder of integer division (function) |
Synopsis
namespace std { using size_t = /*see description*/ ; using div_t = /*see description*/ ; using ldiv_t = /*see description*/ ; using lldiv_t = /*see description*/ ; } #define NULL /*see description*/ #define EXIT_FAILURE /*see description*/ #define EXIT_SUCCESS /*see description*/ #define RAND_MAX /*see description*/ #define MB_CUR_MAX /*see description*/ 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 // 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 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); // 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); // C standard library algorithms void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, /*c-compare-pred*/ * compar); void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, /*compare-pred*/ * compar); void qsort(void* base, size_t nmemb, size_t size, /*c-compare-pred*/ * compar); void qsort(void* base, size_t nmemb, size_t size, /*compare-pred*/ * compar); // low-quality random number generation int rand(); void srand(unsigned int seed); // 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); lldiv_t div(long long int numer, long long int denom); ldiv_t ldiv(long int numer, long int denom); lldiv_t lldiv(long long int numer, long long int denom); }