Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for a snapshot of the develop branch, built from commit 31c6e1f53a.


// Copyright (C) 2009-2012 Lorenzo Caminiti
// Distributed under the Boost Software License, Version 1.0
// (see accompanying file LICENSE_1_0.txt or a copy at
// Home at


#include <boost/typeof/std/string.hpp> // No need to register `boost::function`.
#include <boost/function.hpp>
#include <string>

const std::string& identity_s(const std::string& x) // Function (as pointer).
    { return x; }

int identity_i_impl(int x) { return x; }
int (&identity_i)(int) = identity_i_impl; // Function reference.

double identity_d_impl(double x) { return x; }
boost::function<double (double)> identity_d = identity_d_impl; // Functor.

#endif // #include guard