🚀 go-pugleaf

kaelin@bridge.com (Kaelin Colclasure) writes:

>What behavior does the draft standard condone for the following
>scenario:
>
>1) In a header file, an inline function is defined to contain a local
>static, like so:
>
>	inline int *
>	foo()
>	{
>	    static int i;
>	    return &i;
>	}
>
>2) Two seperate modules include this header file, call them A and B.
>A "initializes" foo():
>
>	#include "foo.h"
>	...
>	*foo() = 1;
>	...
>
>3) B calls foo(), dereferences the pointer returned and prints its
>value:
>
>	#include <iostream.h>
>	#include "foo.h"
>	...
>	cerr << "*foo() = " << *foo() << endl;
>	...
>
>Some data points:
>
>MSVC++:	*foo() = 1
>G++:	*foo() = 0
>Sun C++:*foo() = 0
>CFront:	"sorry, not implemented"
>
>My intuition is that MSVC++ is doing the "right" thing (gasp), and what
>"should" be the standard thing-- but I realize that the behavior I
>want requires mangling a global variable name or the moral
>equivalent.  I want to know if the standard requires this or leaves
>the behavior implementation defined...

The standard mandates the behaviour of g++ and Sun C++.
The reason is that an inline function by default has static linkage,
and so each translation unit gets its own copy.
To get the behaviour exhibited by MSVC++ from a draft
standard-conforming compiler, you would have to explicitly declare foo() as
`extern'.  That is, you would have to change the definition of foo() from

	inline int * foo() { ... }

to 

	extern inline int * foo() { ... }

--
Fergus Henderson             	WWW: http://www.cs.mu.oz.au/~fjh
fjh@cs.mu.oz.au              	PGP: finger fjh@128.250.37.3
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