On 17/01/2008, Richard Guenther wrote: > > Well, a language lawyer can probably clear things up. From a look > at the std it looks like w/o a previous declaration the above should > be invalid. And at a different point it suggests the decl becomes > available.
Yes, at the point of instantiation of Foo<int> the friend is declared, and can then be found by ADL because Foo<int> is an associated type. The reference parameter 'x' doesn't cause an instantiation, only 'weird' does. However, see the discussion in section 9.2.2 of Vandevoorde and Josuttis' C++ Templates book and the footnote saying the standard isn't exactly clear. I'm only guessing, but EDG's behaviour could be related to their interpretation of DR329 http://www.open-std.org/jtc1/sc22/wg21//docs/cwg_defects.html#329 I'm not sure which interpretation is correct, but GCC's seems reasonable to me. Jon
