text: #pragma once
  
  #include <stddef.h>
  
  #ifdef __cplusplus
  extern "C" {
  namespace std {
  #endif
  
  int atoi(const char *s);
  
  // only base 2, 8, 10 and 16 are supported
  // for others the result can be undefined.
  // And only base 10 is considered as signed int.
  void itoa(int num, char *s, int base);
  void ftoa(double num, char *s, int afterpoint);
  int min(int, int);
  int max(int, int);
  int abs(int a);
  
  int benchmark_get_heap_usage();
  int benchmark_get_heap_area();
  void *malloc(size_t size);
  void *realloc(void *ptr, size_t size);
  void free(void *ptr);
  
  void atexit(void (*)(void));
  void exit(int status);
  
  #ifdef __cplusplus
  } // namespace std end
  } // extern C end
  #endif
  