MSVC vs {fmt} results

[hpwxf]

In https://github.com/haveneer/cpp-advanced-training/blob/master/src/format/format--unittest.cpp MSVC and lib {fmt} results differ in two cases. Needs investigation...

[hpwxf]

For example std::format("{:#}", 3.0); should return 3. or 3.0 ?

• https://en.cppreference.com/w/cpp/utility/format/formatter#Standard_format_specification is not explicit
• in libfmt, this subject has been solved as
  • Alternate form of general format is missing trailing zeros fmtlib/fmt#1797
  • https://github.com/fmtlib/fmt/blob/00a57a9f8f06b7eb7f95dadbbeaa77827cb1384e/test/format-test.cc#L667
• in C++ standard
  • http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0645r10.html
  • https://isocpp.org/files/papers/N4860.pdf#page733 section 20.20.2.2 .6

Normally, a decimal-point character appears in the result of these conversions only if a digit follows it. In addition, for g and G conversions, trailing zeros are not removed from the result