Стандартная библиотека заголовок <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
}