// An example of defining a postconstructor for a class which // uses boost::signals2::deconstruct as its factory function. // This example expands on the basic postconstructor_ex1.cpp example // by passing arguments to the constructor and postconstructor. // // Copyright Frank Mori Hess 2009. // Use, modification and // distribution is subject to the Boost Software License, Version // 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // For more information, see http://www.boost.org #include <boost/shared_ptr.hpp> #include <boost/signals2/deconstruct.hpp> #include <iostream> #include <sstream> #include <string> namespace bs2 = boost::signals2; namespace mynamespace { class Y { public: /* This adl_postconstruct function will be found via argument-dependent lookup when using boost::signals2::deconstruct. */ template<typename T> friend void adl_postconstruct(const boost::shared_ptr<T> &, Y *y, const std::string &text) { y->_text_stream << text; } void print() const { std::cout << _text_stream.str() << std::endl; } private: friend class bs2::deconstruct_access; // give boost::signals2::deconstruct access to private constructor // private constructor forces use of boost::signals2::deconstruct to create objects. Y(const std::string &text) { _text_stream << text; } std::ostringstream _text_stream; }; } int main() { boost::shared_ptr<mynamespace::Y> y = bs2::deconstruct<mynamespace::Y>("Hello, ").postconstruct("world!"); y->print(); return 0; }