[C++-sig] GNU gettext and "_"

[David Abrahams]

----- Original Message -----
From: "Pearu Peterson" <pearu at cens.ioc.ee>

> "Obvious" to me would be to use the same convention as used in Python
> slice object, that is,
>
>   x[:y]   would be x.slice(None,y)
>   x[:y:]  would be x.slice(None,y,None)
>   etc.

Unfortunately not equivalent.

>>> range(10)[slice(None:3)]
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
TypeError: sequence index must be integer

> > I suppose we could check "#if defined(_)" and supply some other symbol
for
> > those people who need gettext compatibility.
>
> -1. It would mean that there will be two groups of BPL users who cannot
> use each other codes, very roughly speaking.

No, the method that doesn't collide with "_" would be ugly, but would work
everywhere (for now).
However, I don't really want to bend over backwards to stay out of the way
of gettext. There is simply no way to protect yourself from macros. If we
invent a name that we think is safe, say, "nil", somebody will #define nil
0. As a matter of fact, Apple does that in their system headers.

So, what I'm thinking of is something like:

enum slice_nil
{
#ifndef _
    _
#endif
};

So people using systems where "_" is defined can write slice_nil() instead.

-Dave