Question

How to use variadic function template in C++

Answer 1

#include <iostream>

void print() {
    std::cout << "void print()";
}
 
template <typename T, typename... Types>
void print(T var, Types... args) {
    std::cout << "var: " << var << "\n";
 
    print(args...);
}
 
int main() {
    print(9, 324, 98.73, 7178, "c++");
    std::cout << "\n-----\n";
    print(5);
    std::cout << "\n-----\n";
    print();
}





/*
run:

var: 9
var: 324
var: 98.73
var: 7178
var: c++
void print()
-----
var: 5
void print()
-----
void print()

*/

 

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Answer 2

#include <iostream>

template<typename T>
T f(T v) {
    return v;
}

template<typename T, typename... Args>
T f(T first, Args... args) {
    return first + f(args...);
}
 
int main() {
    long sum = f(1, 2, 3, 4);

    std::cout << sum << "\n";
}





/*
run:

10

*/

 

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