[C++] temporary string + int

gcc: get warning for `std::string("foo" + 42);`?

#include <iostream>

int main()
{
    std::cout << ("hi" + 42) << std::endl;
}

a.k.a

#include <iostream>
#include <string>

int main()
{
    std::cout << 42["hi"] << std::endl;
}