On 03.01.2015 21:40, Alejandro Exojo wrote: > El Saturday 03 January 2015, Reinhardt Behm escribió: >> I have used them to put together a commonly used header (see attached >> project.h), that I also use as a precompiled header. >> This way all the required <Qt...> headers are automatically included. > Why do such thing? Adding a `using namespace std` in a common header seems > like a terrible idea to begin with. You should import namespaces only when you > need them, and as much scoped as you can. Or just using what you want (`using > std::cout` if you only use that). Seems a recipe for future name clashes that > will give strange compilation errors if you use reasonably name variables. > > Including all the Qt headers is something that I don't understand either. Even > with precompiled headers. > A precompiled header is of not much use if it does not include the most biggest and most used headers. And the Qt-headers are big.
I did not have many name clashes even with "reasonably named variables" or perhaps because of that, using many different programming languages in the past 30+ years and Qt since 2.x. Most of those do not have the concept of namespaces. The Qt people have done a good job of not polluting the global namespace. If other libraries have such a problems, I have found that often they have other even worse deficiencies. So I will avoid them. There is no room in critical software like avionics for which I often work for such stuff. The "using namespace std" is more of historic relict. When using Qt I really do not use much of the std namespace anymore. Time to remove it in 2014. -- Reinhardt, wishing everyone a successful and happy new year. _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
