> -----Original Message----- > From: Ville Voutilainen [mailto:[email protected]] > Sent: Wednesday, 24 January 2018 1:11 PM > To: Mitch Curtis <[email protected]> > Cc: Alexander Nassian <[email protected]>; development@qt- > project.org > Subject: Re: [Development] #pragma once > > On 24 January 2018 at 12:34, Mitch Curtis <[email protected]> wrote: > > > > > >> -----Original Message----- > >> From: Ville Voutilainen [mailto:[email protected]] > >> Sent: Wednesday, 24 January 2018 11:25 AM > >> To: Alexander Nassian <[email protected]> > >> Cc: Mitch Curtis <[email protected]>; [email protected] > >> Subject: Re: [Development] #pragma once > >> > >> On 24 January 2018 at 12:22, Alexander Nassian <nassian@bitshift- > >> dynamics.com> wrote: > >> > Maybe because it’s not part of the C++ standard? > >> > >> #pragma once is not a replacement for include guards. > > > > Why not? > > > >> It's not part of the C++ standard because it doesn't always work > > > > In which ways? My quick search gave me these: > > > > https://stackoverflow.com/a/1946730/904422 > > https://en.wikipedia.org/wiki/Pragma_once#Caveats > > That wikipedia link seems to describe the problems fairly accurately.
Do we have that issue in Qt? > >> and modules are a superior solution anyway. > > How so? > > Because you can import the same module multiple times without concerns > about re-definitions, and that import is much faster than parsing a header > file. _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
