id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
1067	Function needs to use pass-by-reference internally	Douglas Gregor	Douglas Gregor	"Boost.Function uses pass-by-value internally for the function object. While it is unspecified how many times the function object would be copied, we should still minimize this amount. The following code snippet illustrates how many copy constructions are performed.

struct Functor
{
    Functor(void)
        { std::cout << ""Functor constructor ("" << this << ')' << std::endl; }
    Functor(const Functor&)
        { std::cout << ""Functor copy constructor ("" << this << ')' << std::endl; } 
    ~Functor(void)
        { std::cout << ""Functor destructor ("" << this << ')' << std::endl; }

    void operator()(void) const
        { std::cout << ""Hello world!"" << std::endl; } 

    std::string memfunc(void) const
        { return std::string(""hello world!!!!!!""); }
};

int main(void)
{
    Functor func;
    boost::function0<void> f(func);

    return 0; 
}"	Bugs	closed	Boost 1.35.0	function	Boost 1.34.0	Optimization	fixed