TITLE: including via <header> versus <header.h>

(Newsgroups: comp.lang.c++.moderated, 11 Jan 99)


NARAN: sbnaran@localhost.localdomain (Siemel Naran)

>>> My general purpose headers don't have the .h suffix.  Eg,
>>>   #include <fvector>
>>> Anything wrong with this?


HARMON: David Harmon

>> For your own headers should be
>>    #include "fvector"


THOMAS: Biju Thomas <bijuthom@ibm.net>

>There is no such requirement, AFAIK. The standard leaves the search
>criteria for both the <header> and "header" styles upto the
>implementation.
>
>As a matter of style, I agree with your point.


CLAMAGE: Steve Clamage <clamage@Eng.Sun.COM>

It's more than a matter of style.

If you write
    #include <stdhdr>
where stdhdr is the exact spelling of one of the standard headers,
with or without a suffix as appropriate, you should get the
standard header. If you write "stdhdr" instead of <stdhdr>
the standard makes no statement about what will happen.

Similarly, if you write
    #include <otherhdr>
where otherhdr is not the exact spelling of one of the standard
headers, the standard makes no promises about what will happen.
But implementations commonly provide additional system headers
that will be found when you use angle brackets.

A valid implementation might be able to find only system headers 
if you use angle brackets, and never find system headers if you
use quotes.

Your best chance for a working program is to use angle brackets
only for standard headers (or other system headers as documented
by the implementation), and to use quotes for all of your own
headers.

An apparent exception to this guideline is when you want to
replace a system header with your own version. Doing so places
you completely outside the realm of any promises made by the
C++ standard or your C++ vendor. You don't get to complain
when your program fails mysteriously. :-)