Return multiple values
1234567891011121314151617 | #include <tuple>
std::tuple<int, bool, float> foo()
{
return std::make_tuple(128, true, 1.5f);
}
int main()
{
std::tuple<int, bool, float> result = foo();
int value = std::get<0>(result);
int obj1;
bool obj2;
float obj3;
std::tie(obj1, obj2, obj3) = foo();
} |
This pattern is licensed under the CC0 Public Domain Dedication.
Intent
Return multiple values of different types from a function.
Description
The foo function on lines 3–6 returns a
std::tuple representing multiple values
of different types. We make use of the
std::make_tuple utility function
to create the std::tuple object.
On line 10, we call this function and store the result. We then get
the first of the returned values with std::get
on line 11.
Alternatively, on line 16 we use std::tie
to assign the return values to each of the given objects.
This may not be possible if the objects cannot be constructed
beforehand and it removes the possibility of copy elision.
If the values are closely and logically related, consider composing
them into a struct or class type.
