Declaring a default templated function

Question

Suppose I have the following:

// Foo.h
struct Foo {};

// Bar.h
struct Bar {
    template <typename T, typename = typename std::enable_if<std::is_base_of<Foo, T>::value>::type>
    void foobar();
};

// Bar.hpp
// ...?
void Bar::foobar() {}

How do I declare the foobar function on Bar.hpp?

"*How do I declare the foobar function on Bar.cpp?*" - you don't. See [Why can templates only be implemented in the header file?](https://stackoverflow.com/questions/495021/) — Remy Lebeau, Jul 09 '20 at 04:06
why do you want a separate implementation? Why not implementing it at the point of declaration? — bolov, Jul 09 '20 at 04:12

score 0 · Answer 1 · answered Jul 09 '20 at 04:28

0

The default argument must be specified just once. So do this:

template <class T, class>
void Bar::foobar() {}

answered Jul 09 '20 at 04:28

bolov

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Declaring a default templated function

1 Answers1