Re: is this a bug?

[llewelly]

Ulrich Lauther <lauther@mchp.siemens.de> writes:

> when I include iostream, the macro _PAIR_H is defined.

This is not a bug. All names begining with an underscore followed by
    an uppercase letter are reserved to the implementation for any
    use. So g++ is allowed to define _PAIR_H .

> I would have expected STL_PAIR_H or something similar, but not just
> _PAIR_H
[snip]

The implementation isn't allowed to use a name like 'STL_PAIR_H'; it
    does not contain a double underscore, it does not begin with an
    underscore followed by an uppercase letter. If g++ *did* define
    STL_PAIR_H (which it doesn't) that *would* be a bug.

See 17.4.3.1.2 for reference.