[Bug c++/58815] Casting/Conversion operator for std::decimal not supported

[janis at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58815

--- Comment #4 from Janis Johnson <janis at gcc dot gnu.org> ---
I vaguely remember a problem with those conversion and have no idea now what it
was, but I'll try to find something in the mailing list archives.

<decimal/decimal> includes a workaround:

  /// Non-conforming extension: Conversion to integral type.
  long long decimal32_to_long_long(decimal32 __d);
  long long decimal64_to_long_long(decimal64 __d);
  long long decimal128_to_long_long(decimal128 __d);
  long long decimal_to_long_long(decimal32 __d);
  long long decimal_to_long_long(decimal64 __d);
  long long decimal_to_long_long(decimal128 __d);