Question

I currently use this code in C++ to call a function pointer if it isn’t null (I have a few events like onCreate, onDestroy, etc, that are function pointers that can be assigned):

#define AssertiveCall(_fn, _args) \
    { \
        if (_fn != nullptr) \
        { \
            return (_fn##_args); \
        } \
    }

I would like to convert this into a template, so that I still get the benefit of shorthand but without the ugliness of the #define macro. How could I do it?

Answer 1

For reference, an implementation with variadic templates – in case somebody else has a similar problem and can use variadic templates:

template <typename Return, typename ...Parameters, typename ...Args>
auto AssertiveCall(Return (*function)(Parameters...), Args&& ...args)
    -> Return
{
    if (function != nullptr) {
        return (*function)(std::forward<Args>(args)...);
    } else {
        return Return{};
    }
}