Default template parameter with a default value?

Question

We can have the following and it is valid:

template<std::size_t Size = 10>
fn(){...}


template<typename Size = std::size_t>
fn() {...}

But how to do this?

template<typename Size = std::size_t=10>
fn() {...}

Answer 1

A template parameter is either a type or a value, it isn't both.

You can do it with two parameters

template<typename Size = std::size_t, Size s = 10>