Hello Alexander, Wednesday, April 4, 2007, 12:16:34 AM, you wrote: [snip]
A global or thread-scope variable can be used to save a pointer to an object holding all references (hello and world in the example). Actually, the first version was based on that technique.
This code demonstrates how it works under the hood:
// Somewhere in the library __thread void* g_args;
// User code BOOST_SCOPE_EXIT( (hello)(world) ) // line 1 /* Expands to: struct args_line1 { std::string &hello, &world; } args_line1 = { hello, world }; g_args = &args_line1; struct scope_exit_line1 { void* m_args; ~scope_exit() { struct args_line1* p = (struct args_line1*)m_args; doit(p->hello, p->world); } static void doit(std::string& hello, std::string& world) */ { // scope(exit) code } BOOST_SCOPE_EXIT_END // line 5 /* } scope_exit_line5 = { g_args }; */
Without g_args, it's not easy to know a name of args_line1 at line 5.
Although a next instruction after writing to g_args is reading it, thread-safety is a problem and that's why I abandoned this approach.
What if something like that: BOOST_SCOPE_EXIT // line 1 /* Expands to: struct _scope_guard_class_line1 { ~_scope_guard_class_line1() { */ { // scope(exit) code } BOOST_SCOPE_EXIT_END((hello)(world)); // line 5 /* Expands to: } std::string& hello; std::string& world; } _scope_guard_line5 = { hello, world }; */ While the variable list is now in the end, no ids needed at all. [snip] -- Best regards, Andrey mailto:andysem@mail.ru