token pasting (was: how widespread is this cpp bug?)

[Henry Spencer]

In article <1747 at solo3.cs.vu.nl> maart at cs.vu.nl (Maarten Litmaath) writes:
>Why didn't the ANSI committee legalize that current practice, instead of
>defining a new paste operator (##)?

Because that current practice was current practice only on some compilers;
on others it did not work and could not easily be implemented.  In
particular, it is hard to make it work under a token-based preprocessor.
It's also hard to define in a precise way that doesn't cause trouble with
other things.  (He who does not value a precise definition of this stuff
has never tried to implement it.)
-- 
SunOSish, adj:  requiring      |     Henry Spencer at U of Toronto Zoology
32-bit bug numbers.            | uunet!attcan!utzoo!henry henry at zoo.toronto.edu