🚀 go-pugleaf

gaulke@uiucdcsp.CS.UIUC.EDU (Dave Gaulke) writes:
>I have found a problem with C++ when using it to write code for the DMD.
>The following is part of the output of the preprocessor when including the
>file <blit.h> for a simple program.
>
>typedef int (*ptr_fint)();
>main() { (*((int (*)())((ptr_fint *)0x0071d700)[ 43]))( 1 ); }

The problem is that "int (*)()" in oldC means "pointer to function returning
int" whereas in C++ it means "pointer to function taking no arguments and
returning int".  "typedef int (*ptr_fint)(...);" is the correct declaration
in C++, and presumably there's a macro somewhere in blit.h that uses the
oldC cast "(int (*)())" which should be "(int (*)(...))" in C++.

The other compatibility problem which came up recently was a collision
between a structure tag and a variable (which share one namespace in C++).

Bjarne: is there a CC option that gives you compatibility with oldC in these
two cases?  Also, ANSI C preserves the oldC meaning of "int (*)()" and adds
"int (*)(void)" for functions with no arguments.  Will C++ switch to this
notation?  Does it currently accept this notation?

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint