Template template parameters validity

Question

template <template <typename> class CallbackT,
      typename Functor,
      typename... Args>
decltype(auto) BindImpl(Functor&& functor, Args&&... args)

BindImpl is a template function, and is called like this:

return internal::BindImpl<OnceCallback>(std::forward<Functor>(functor),
                                        std::forward<Args>(args)...);

as far as I know, template template paramaters are not allowed in a template function.

What kind of mechanism is used here?

see source code here

"template template paramaters is not allowed to be used in template function." -- do you have some source on that? I think it should be allowed. — user202729, Aug 06 '20 at 09:44
*"template template paramaters is not allowed to be used in template function"* Citation needed. — HolyBlackCat, Aug 06 '20 at 09:44
Look [here](https://stackoverflow.com/questions/213761/what-are-some-uses-of-template-template-parameters) — gonidelis, Aug 06 '20 at 09:55
If Chinese Wikipedia does indeed say that (seems to be the case), then it's wrong. — HolyBlackCat, Aug 06 '20 at 09:56

score 0 · Answer 1 · answered Dec 28 '21 at 06:58

0

The code is correct, as there is no restriction as the Chinese Wikipedia article describes. Regretfully I cannot update the article, as my IP address is banned. You should delete that sentence if you can.

answered Dec 28 '21 at 06:58

Yongwei Wu

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Template template parameters validity

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