return statement

Terminates the current function and returns the specified value (if any) to the caller.

# Notes

Returning by value may involve construction and copy/move of a temporary object, unless copy elision is used. Specifically, the conditions for copy/move are as follows:

The expression is move-eligible if it is a (possibly parenthesized) identifier expression that names a variable of automatic storage duration whose type is

and that variable is declared

If the expression is move-eligible, overload resolution to select the constructor to use for initialization of the returned value or, for co_return, to select the overload of promise.return_value()(since C++20) is performed twice :

If the expression is move-eligible, it is treated as an xvalue (thus overload resolution may select the move constructor).

If expression is a prvalue, the result object is initialized directly by that expression. This does not involve a copy or move constructor when the types match (see copy elision).

# Example

#include <iostream>
#include <string>
#include <utility>
 
void fa(int i)
{
    if (i == 2)
        return;
    std::cout << "fa("<< i << ")\n";
} // implied return;
 
int fb(int i)
{
    if (i > 4)
        return 4;
    std::cout << "fb(" << i << ")\n";
    return 2;
}
 
std::pair<std::string, int> fc(const char* p, int x)
{
    return {p, x};
}
 
void fd()
{
    return fa(10); // fa(10) is a void expression
}
 
int main()
{
    fa(1); // prints its argument, then returns
    fa(2); // does nothing when i == 2, just returns
 
    int i = fb(5); // returns 4
    i = fb(i);     // prints its argument, returns 2
    std::cout << "i = " << i << '\n'
              << "fc(~).second = " << fc("Hello", 7).second << '\n';
 
    fd();
}
 
struct MoveOnly
{
    MoveOnly() = default;
    MoveOnly(MoveOnly&&) = default;
};
 
MoveOnly move_11(MoveOnly arg)
{
    return arg; // OK. implicit move
}
 
MoveOnly move_11(MoveOnly&& arg)
{
    return arg; // OK since C++20. implicit move
}
 
MoveOnly&& move_23(MoveOnly&& arg)
{
    return arg; // OK since C++23. implicit move
}

# Defect reports

DR	Applied to	Behavior as published	Correct behavior
CWG 1541	C++98	expression could not be omitted if the return type is cv-qualified void	it can be omitted
CWG 1579	C++11	return by converting move constructor was not allowed	converting moveconstructor lookup enabled
CWG 1885	C++98	sequencing of the destruction of automatic variables was not explicit	sequencing rules added

return statement

# Notes

# Example

# Defect reports

# See also