converting-variadics-wrapper

main.cpp

#include <cstdio> // printf

struct mytype {
	int value;
	operator int() const {return value;}
};


template<typename T> struct argument_type_helper{using type = T;};
template<> struct argument_type_helper<mytype>{using type = int;};

template<typename T> using argument_type = typename argument_type_helper<T>::type;

template<typename T> argument_type<T> argument_cast(const T& arg) {return arg;}

template<typename...Args>
void converting_printf(const char* format, const Args&...args) {
	std::printf(format, argument_cast(args)...);
}


int main() {
	mytype myvar{42};
	converting_printf("mytype: %d, some int: %d\n", myvar, 23);
}

Output:
mytype: 42, some int: 23