Multiple return values

C++17 gives us an elegant way to return multiple values from a function using structured binding.

Here’s how we can declare a function that returns 3 values:

template
auto ReturnThree(T t) -> tuple
{
    return {t / 9, t / 3, t};
}

This function takes one argument of type

T

, and returns a

tuple<T, T, T>

of 3 values.

In order to get the return values in C++11 we would have to write the following:

tuple<int, int, int> t = ReturnThree(9);

But with C++17 and structured binding syntax we can write:

auto [t1, t2, t3] = ReturnThree(9);

Much cleaner code this way 🙂

Complete listing:

#include 
using namespace std;

template
auto ReturnThree(T t) -> tuple
{
    return {t / 9, t / 3, t};
}

int main(int argc, char** argv)
{
    tuple t = ReturnThree(9); // Old and rusty
    auto [t1, t2, t3] = ReturnThree(9); // New and shiny
    return 1;
}