Implement formattable, range_format, and format_kind - #4116

Implement formattable, range_format, and format_kind#4116

Stephan T. Lavavej (StephanTLavavej) merged 3 commits into

microsoft:mainmicrosoft/STL:mainfrom

frederick-vs-ja:formattable-format_kindfrederick-vs-ja/STL:formattable-format_kindCopy head branch name to clipboard