[temp.param] Replace tt

[hewillk]

https://eel.is/c++draft/temp.param

There are many here:

type-tt-parameter
variable-tt-parameter
concept-tt-parameter

which comes from https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p2841r7.pdf.
This looks like an abbreviation of "template template".
But it seems too concise and looks a bit strange.
Would it be more readable and understandable if it were reverted to "template template" (although it's more verbose)? or slightly less concise, such as "templ-templ"?

[eisenwave]

I'm not hugely to variable-template-template-parameter, but I don't think it's strictly an improvement over the status quo. We also have various grammar nonterminals that are abbreviated, like x-seq, pp-number, etc. The tt fits right in.

Overall, meh.

[jensmaurer]

These particular grammar terms were reviewed and approved by at least CWG and the new terms are not obviously better. If you feel strongly, submit a paper to CWG, with rationale.