Implement LWG-4257: Stream insertion for chrono::local_time should be constrained by vmichal · Pull Request #5895 · microsoft/STL (original) (raw)

Constrain operator<<(basic_ostream, chrono::local_time), require validity of underlying expression.
Add tests.

Fixes #5854

Note: I've noticed that more often than not, requires clauses in the STL code are written before the function name, repeating the parameter list when necessary. I have placed the constraint after the function name and omitted the repetition of the parameter list. Please let me know whether this is preferred or not.