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copied!<p>If you are simply trying to set the return type, make it a template argument. This way you can change everything related to the return type without actually changing the function. You can put a default return type if you want like in this example.</p> <pre><code>template <class R = int, class T> R f(T&& x) { ... return h2(y2, y3); } </code></pre> <hr> <p>The code below demonstrates it's effectiveness.</p> <p><strong>DEMO CODE:</strong></p> <pre><code>#include <iostream> #include <iomanip> template <class T, class S> T h2(T& x, S& y) { return x + y; } template <class R = int, class T> R f(T& x) { auto y2 = x; auto y3 = x; return h2(y2, y3); } int main(int argc, char** argv) { int x = 7; std::string str = "test! "; auto d = f<double>(x); auto i = f(x); // use default type (int) auto s = f<std::string>(str); std::cout << std::fixed << std::setprecision(4); std::cout << "double: " << d << std::endl; std::cout << "int: " << i << std::endl; std::cout << "string: " << s << std::endl; return 0; } </code></pre> <hr> <p><strong>OUTPUT:</strong></p> <pre><code>double: 14.0000 int: 14 string: test! test! </code></pre> <hr> <p>Unfortunately, the exact functionality you are looking for does not exist (yet) and is not part of the C++0x spec. However, it is possible this may be part of the C++1x spec when it is drafted. until then, stick to templates.</p>

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