Standard library header <cstdlib>

namespace std {
 using size_t = /* see description */; // freestanding
 using div_t = /* see description */; // freestanding
 using ldiv_t = /* see description */; // freestanding
 using lldiv_t = /* see description */; // freestanding
}
 
#define NULL /* see description */ // freestanding
#define EXIT_FAILURE /* see description */ // freestanding
#define EXIT_SUCCESS /* see description */ // freestanding
#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 */ = // exposition only
 int(const void*, const void*);
 extern "C++" using /* compare-pred */ = // exposition only
 int(const void*, const void*);
 
 // start and termination
 [[noreturn]] void abort() noexcept; // freestanding
 int atexit(/* c-atexit-handler */* func) noexcept; // freestanding
 int atexit(/* atexit-handler */* func) noexcept; // freestanding
 int at_quick_exit(/* c-atexit-handler */* func) noexcept; // freestanding
 int at_quick_exit(/* atexit-handler */* func) noexcept; // freestanding
 [[noreturn]] void exit(int status); // freestanding
 [[noreturn]] void _Exit(int status) noexcept; // freestanding
 [[noreturn]] void quick_exit(int status) noexcept; // freestanding
 
 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, // freestanding
 size_t nmemb, size_t size, /* c-compare-pred */* compar);
 void* bsearch(const void* key, const void* base, // freestanding
 size_t nmemb, size_t size, /* compare-pred */* compar);
 void qsort(void* base, size_t nmemb, size_t size, // freestanding
 /* c-compare-pred */* compar);
 void qsort(void* base, size_t nmemb, size_t size, // freestanding
 /* compare-pred */* compar);
 
 // low-quality random number generation
 int rand();
 void srand(unsigned int seed);
 
 // absolute values
 constexpr int abs(int j); // freestanding
 constexpr long int abs(long int j); // freestanding
 constexpr long long int abs(long long int j); // freestanding
 constexpr /* floating-point-type */
 abs(/* floating-point-type */ j); // freestanding-deleted
 
 constexpr long int labs(long int j); // freestanding
 constexpr long long int llabs(long long int j); // freestanding
 
 constexpr div_t div(int numer, int denom); // freestanding
 constexpr ldiv_t div(long int numer, long int denom); // freestanding
 constexpr lldiv_t div(long long int numer, long long int denom); // freestanding
 constexpr ldiv_t ldiv(long int numer, long int denom); // freestanding
 constexpr lldiv_t lldiv(long long int numer, long long int denom); // freestanding
}