🚀 go-pugleaf

greghunt@zeta.org.au writes:

> We are not attempting to support linkage between compilers - which is
> both unfortunate and too hard - but we have the prospect of different
> linkages being generated by the same compiler at different times -
> which seems unnecessary.

That is a *very* good point.

Regardless of whether or not a C++ compiler is or is not required to
support interfacing with C, a stand-alone C++ program may contain
"C" linkage-specifications.  The C++ standard *must* make it clear
whether or not a program such as the following is strictly conforming.

	void foo(void (*func)()) { (*func)(); }
	void bar() {}
	extern "C" void baz() {}

	int main() {
		foo(bar);
		foo(baz);
		return 0;
	}

According to my reading of the ARM and the current draft standard, this
program is strictly conforming.  The semantics of the `foo(baz)' are
well-defined for exactly the same reason that the semantics of `foo(bar)' are
well-defined.

I think it would be a bad mistake if there committee were to decide to
disallow this program, or give it undefined behaviour.
It would break a significant amount of code and impose a continuing
hardship on C++ programmers, with very few compensating benefits.

-- 
Fergus Henderson              | Designing grand concepts is fun;
fjh@cs.mu.oz.au               | finding nitty little bugs is just work.
http://www.cs.mu.oz.au/~fjh   | -- Brooks, in "The Mythical Man-Month".
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