Interesting. Even in /permissive- mode, though, it seems to be skipping the parser for requires-clauses, template default arguments, and probably some other stuff in the template-head.
https://godbolt.org/z/751cc9


On Wed, Jul 15, 2020 at 5:20 PM Hyman Rosen <hyrosen@mail.com> wrote:
On Wed, Jul 15, 2020 at 4:35 PM Arthur O'Dwyer via Std-Proposals <std-proposals@lists.isocpp.org> wrote:
Just to drive this point home (and because I know someone else will say it if I don't):
The body of this function template is "syntax error syntax error" (with no semicolon at the end). MSVC accepts it happily, because MSVC doesn't parse templates.

It does if you invoke it correctly: <https://godbolt.org/z/Gz9eYv>