ScopeGuard Implementation

3 Jul 2002

      Hi,

Recently I've tried to implement Andrei's ScopeGuard (see http://www.cuj.com/experts/1812/alexandr.htm?topic=experts for details) with boost.function and boost.bind. Is there anything wrong with it? Thanks for reviewing. 

#include 
#include 
#include 
#define ON_BLOCK_EXIT(x) scoped_guard guard##__LINE__(::boost::bind##x)

class scoped_guard: ::boost::noncopyable
{
private:
        typedef const ::boost::function<void> f_type;
		// reference might cause crash

        bool dismissed_;
        f_type f_;
public:
        scoped_guard(f_type& v): f_(v), dismissed_(false) {}
        ~scoped_guard() throw()
        {
                if(!dismissed_)
                   try {f_();}
                   catch(...) {}
        }

        void dismiss() throw() { dismissed_ = true; }
};

With the macro ON_BLOCK_EXIT, we can easily use it like this:

// ...
#include 
int main()
{
        FILE* fp = fopen("hello.txt", "r");
        ON_BLOCK_EXIT((fclose, fp));
        //scoped_guard guard(boost::bind(fclose, fp));
        return 0;
}　　

　　　　　　　　　　　　　　Jon Wang
					 	  babysloth@c-view.org
   　　　　　　　　　　　 　2002-07-03