compilation warning # pragma once

[Subrat]

Hello,
I have used #pragma once in a header file.
During compilation I get a warning : #pragma once is obsolete.
How do I switch off this warning, without making any change to my make file?

Thanks in Advance,
Subrat

 

[red floyd]

Hello,
I have used #pragma once in a header file.
During compilation I get a warning : #pragma once is obsolete.
How do I switch off this warning, without making any change to my make file?

Thanks in Advance,
Subrat

Wrong group. #pragma's are implementation specific. How to disable
warnings is implementation specific. Try a group with microsoft or
vc in its name.

See FAQ 5.9 http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9

 

[Jim Langston]

Hello,
I have used #pragma once in a header file.
During compilation I get a warning : #pragma once is obsolete.
How do I switch off this warning, without making any change to my make
file?

Easiest way, go into the header file, remvoe #pragma once and replace it
with the proper include guards.
#ifndef MYFILE_H
#define MYFILE_H

// header here

#endif

MYFILE_HEADER
is also sometimes used.

 

[James Kanze]

Easiest way, go into the header file, remvoe #pragma once and replace it
with the proper include guards.
#ifndef MYFILE_H
#define MYFILE_H

// header here

MYFILE_HEADER
is also sometimes used.

Many different conventions are sometimes used (inluding some
which are formally illegal, e.g. _MYFILE_H). The important
point is to avoid the risk of collisions. For this reason, most
libraries will try to munge the name of the library into the
guard (e.g. BOOST_..._INCLUDED); anything really professional
will probably include some sort of random sequence as well. (I
get toto_hh_20080702Jbqi2me5hF1pQrgColbxnIMk for a file toto.hh,
although I'll get something else if I create it again; the last
24 characters are generated from input from /dev/random.
Another possibility might be an MD-5 or SHA-1 digest of the
hostname and the full pathname from the root, or the filename,
programmer name and the current time and date.)