Can std::is_invocable be emulated within C++11?

Question

I\'d like to use std::is_invocable, however we are using c++11 standard, while is_invocable is available only from c++17.

Is there any way to emulate the functionali

Answer 1

You can try this implementation:) Taken from boost C++ libraries. I've tested it with VS2017 with standard C++14.

template 
struct is_invocable :
    std::is_constructible<
        std::function,
        std::reference_wrapper::type>
    >
{
};

template 
struct is_invocable_r :
    std::is_constructible<
        std::function,
        std::reference_wrapper::type>
    >
{
};