std::exception Interoperability

["Erik Cassel" <erik@...>]

I have patched Lua 5.1 to seamlessly work with std::exception. 

This lets me throw an std::exception-derived object from anywhere in C++
code. Lua will catch it and translate it appropriately in
luaD_rawrunprotected(). 

Also, Lua uses an std::exception-derived class to throw Lua errors. This
means I can catch errors thrown by Lua (as in lua_touserdata).


The benefits of this approach are:

1)	I don't have to write exception handlers in every entry point in my
code. If my code is based on std/boost then I can be confident that
exceptions thrown by my code will be handled by Lua. I don't have to
translate them into lua_error() calls.

2)	It is perfectly safe for me to intercept an exception thrown by Lua.
Since Lua now throws std::exception-derived objects I can catch and inspect
errors with a catch(std::exception&) clause. Moreover, if I decide *not* to
re-throw the exception, then Lua automatically pops the error message from
the stack.


Has anybody else done something like this?  Would it be useful to anybody?
Have I missed something?

I'd be happy to post my patch (and go over implementation details) and/or
show some sample code of how it can be used.

-Erik