Template function in template class

Question

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Can't get the following to compile and I don't really understand why.

Codebolt Code

Snippet here

#include <vector>
#include <string>



template<typename T>
class A
{
    using func_type = bool(int const&);

    template<func_type U, func_type X>
    [[using gnu:cold]]void example(std::vector<std::string>&&);
};


template <typename T>
template <typename A<T>::func_type U, typename A<T>::func_type X>
void A<T>::example(std::vector<std::string>&&)
{

}

Thank you

Answer 1

If you don't want to use the func_type anywhere outside of your class. Then you should change it to

using func_type = bool(*)(int const&);

Remember that the syntax is similar to emplying typedef for function pointers.