Re: what is wrong with this code?

From:
Andrei Alexandrescu <SeeWebsiteForEmail@erdani.org>
Newsgroups:
comp.lang.c++.moderated
Date:
Mon, 20 Jul 2009 03:56:31 CST
Message-ID:
<h3vvlb$v6v$1@news.eternal-september.org>
terry wrote:

This code does not compile unless the second call (at *************) to the
template function is commented out. It causes fatal error C1001: An internal
error has occurred in the compiler in VS2008.

What part of the standard am I violating? Thanks! Is there a work around?
(posted a similar question earlier but perhaps there was too much verbiage -
it would help to know which errors I am making!)

Terry

void f ( void ) {}

struct B
{
     void f ( void ) {}
     typedef void (B::*mfn_t)( void );
};

template <typename T>
void loop( T fn )
{
     fn();
};

int main(int argc, char* argv[])
{
     loop(::f); //loop works OK

     B::mfn_t mfn(&B::f);
     B* pobject = new B;
     ((pobject)->*(mfn)) (); //member function B::f on instance
*pobject can be accessed OK

     //******************************
     loop(((pobject)->*(mfn))); // comment out to get correct compilation
     //******************************

     delete pobject;
     return 0;
}


The result of operators .* and ->* does not have a type. It's an anomaly
and the only place in C++ where an expression does not have a type. All
you can do with the result of these operators is apply the function
operator call to it immediately.

Andrei

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