What is an "exposition-only alias template"?

[JUANDENT]

For instance at https://en.cppreference.com/w/cpp/iterator/forward_iterator:

Definition of this concept is specified via an exposition-only alias template /*ITER_CONCEPT*/.

?
Thanks!

[George P]

Simply amazing what searching the internet can find....

https://stackoverflow.com/questions/34493104/exposition-only-in-the-c-standard

Maybe you should try doing that next time before asking questions that can easily be answered if you actually look.

[JUANDENT]

well thanks