Yea, when we looked into it I recall that it worked fine on all compilers from the last 10 years or something (in fact I remember using #pragma once on Metrowerks Codewarrior more than fifteen years ago). Given we require C++14 I don't think #pragma once is going to be the limiting factor in compiler version portability.
-Todd On Wed, Aug 1, 2018 at 12:01 PM, Sailesh Mukil <sail...@cloudera.com.invalid > wrote: > An advantage of using #pragma once is potential improved compilation > speeds. However, a con is that it's non-standard and therefore, its > behavior can change at any point and can also vary across compilers, > potentially making the code even less portable. > > That being said, since Kudu has been using it for a while and has had no > issues, we can do the same since the potential benefits outweigh the cons. > > On Wed, Aug 1, 2018 at 11:48 AM, Tim Armstrong < > tarmstr...@cloudera.com.invalid> wrote: > > > Todd brought up our include guards on a code review, asking why we don't > > use #pragma once instead: https://gerrit.cloudera.org/#/c/10988/5 . It > > sounds like Kudu has switched to it > > > > #pragma once does seem cleaner and our GCC and Clang versions are modern > > enough to support it. > > > > What do people think about switching to that as the preferred way of > > including headers only once? > > > > - Tim > > > -- Todd Lipcon Software Engineer, Cloudera
