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| // forward example #include <utility> // std::forward #include <iostream> // std::cout // function with lvalue and rvalue reference overloads: void overloaded (const int& x) {std::cout << "[lvalue]";} void overloaded (int&& x) {std::cout << "[rvalue]";} // function template taking rvalue reference to deduced type: template <class T> void fn (T&& x) { overloaded (x); // always an lvalue overloaded (std::forward<T>(x)); // rvalue if argument is rvalue } int main () { int a; std::cout << "calling fn with lvalue: "; fn (a); std::cout << '\n'; std::cout << "calling fn with rvalue: "; fn (0); std::cout << '\n'; return 0; }
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