Re: what is wrong with this code?

From:
"Balog Pal" <pasa@lib.hu>
Newsgroups:
comp.lang.c++.moderated
Date:
Mon, 20 Jul 2009 13:04:46 CST
Message-ID:
<h40c55$2l38$1@news.ett.com.ua>
"terry" <news1@lyonstech.net>

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.


Indeed, here too.

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!)


I simplified the code to the bones, it still makes internal error, that is a
bug in MS compiler -- send them a report so it can be fixed.

- ---
struct B
{
      int f ( void ) {return 0;}
};

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

int main(int argc, char* argv[])
{
      int (B::*mfn)( void ) = &B::f;
      B b;

      loop(b.*mfn); // bug-triggering line
// fatal error C1001: An internal error has occurred in the compiler.
// (compiler file 'msc1.cpp', line 1411)

      return 0;
}
- ---

Cameau reports:
"ComeauTest.c", line 16: error: a pointer to a bound function may only be
used to
           call the function
         Wild Guess: You're calling a member function and forgot the ()'s
        loop(b.*mfn); // bug-triggering line
                ^

that implies the kind of usage is not allowed. (changing it to a call
loop((b.*mfn)());
makes it compile.

In your original example you need a pointer-to-function passed to loop. The
result of .* and ->* operators do not decay to such a pointer (and it would
not be compatible with regular function pointers).

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