text: 
  /* Compiler implementation of the D programming language
   * Copyright (C) 2003-2020 by The D Language Foundation, All Rights Reserved
   * written by Walter Bright
   * http://www.digitalmars.com
   * Distributed under the Boost Software License, Version 1.0.
   * http://www.boost.org/LICENSE_1_0.txt
   * https://github.com/D-Programming-Language/dmd/blob/master/src/root/checkedint.h
   */
  
  #include "dsystem.h"
  
  
  int adds(int x, int y, bool& overflow);
  int64_t adds(int64_t x, int64_t y, bool& overflow);
  unsigned addu(unsigned x, unsigned y, bool& overflow);
  uint64_t addu(uint64_t x, uint64_t y, bool& overflow);
  
  int subs(int x, int y, bool& overflow);
  int64_t subs(int64_t x, int64_t y, bool& overflow);
  unsigned subu(unsigned x, unsigned y, bool& overflow);
  uint64_t subu(uint64_t x, uint64_t y, bool& overflow);
  
  int negs(int x, bool& overflow);
  int64_t negs(int64_t x, bool& overflow);
  
  int muls(int x, int y, bool& overflow);
  int64_t muls(int64_t x, int64_t y, bool& overflow);
  unsigned mulu(unsigned x, unsigned y, bool& overflow);
  uint64_t mulu(uint64_t x, uint64_t y, bool& overflow);
  