[libstdc++] Separate distance(i,j,n) extension from internal routines.

[Phil Edwards]

On Mon, Dec 31, 2001 at 05:28:35PM +0100, Paolo Carlini wrote:
> I have to questions inspired by your patch:
> 1- What about backward/iterator.h ? Should we modify it as I have done for backward/algo.h
> ?

Yeah, probably.  I didn't think of that.  Good catch.


> 2-
> 
> > +#pragma GCC system_header
> 
> Could you possibly explain a bit the meaning of this #pragma? I did'nt put it in my
> ext/algorithm? Should I correct it?

Honestly, I left that in out of habit.  :-)  It's a question to the group
at large:  should the extension headers also receive this special treatment?
I could go either way.

What it does is this:  normally GCC will warn when it sees certain constructs
which are deprecated or not quite standard, especially when -pedantic
is used.  Since we have to play tricks sometimes inside the implementation,
but at the same time we don't want the compiler issuing warnings on library
headers that the user can't do anything about, we flag these headers as
"system headers," which turns off those warnings for these files only.


Phil

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