Adding Functional/OverloadedFunction docs, tests, and examples to libs/.

[SVN r77027]

overloaded_function/test/identity.cpp

@@ -0,0 +1,70 @@
+
+// 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
+// http://www.boost.org/LICENSE_1_0.txt)
+// Home at http://www.boost.org/libs/functional/overloaded_function
+
+#include <boost/functional/overloaded_function.hpp>
+#include <boost/function.hpp>
+#define BOOST_TEST_MODULE TestIdentity
+#include <boost/test/unit_test.hpp>
+#include <string>
+
+//[identity_make_checks
+template<typename F>
+void check(F identity) {
+    BOOST_CHECK( identity("abc") == "abc" );
+    BOOST_CHECK( identity(123) == 123 );
+    BOOST_CHECK( identity(1.23) == 1.23 );
+}
+//]
+
+//[identity_decls
+const std::string& identity_s(const std::string& x) { return x; } // As pointer.
+
+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.
+//]
+
+BOOST_AUTO_TEST_CASE( test_identity ) {
+    //[identity_calls
+    BOOST_CHECK( identity_s("abc") == "abc" );
+    BOOST_CHECK( identity_i(123) == 123 );
+    BOOST_CHECK( identity_d(1.23) == 1.23 );
+    //]
+
+    {
+        //[identity
+        boost::overloaded_function<
+              const std::string& (const std::string&)
+            , int (int)
+            , double (double)
+        > identity(identity_s, identity_i, identity_d);
+
+        // All calls via single `identity` function.
+        BOOST_CHECK( identity("abc") == "abc" );
+        BOOST_CHECK( identity(123) == 123 );
+        BOOST_CHECK( identity(1.23) == 1.23 );
+        //]
+    }
+    
+    {
+        //[identity_make
+        BOOST_AUTO(identity, boost::make_overloaded_function(
+                identity_s, identity_i, identity_d));
+
+        BOOST_CHECK( identity("abc") == "abc" );
+        BOOST_CHECK( identity(123) == 123 );
+        BOOST_CHECK( identity(1.23) == 1.23 );
+        //]
+    }
+
+    //[identity_make_call
+    check(boost::make_overloaded_function(identity_s, identity_i, identity_d));
+    //]
+}
+