[Development] Removing the -c++11 option from configure

Knoll Lars Lars.Knoll at theqtcompany.com
Mon Mar 23 08:32:59 CET 2015

On 21/03/15 21:53, "Thiago Macieira" <thiago.macieira at intel.com> wrote:

>On Saturday 21 March 2015 18:55:52 Edward Sutton wrote:
>> When cross-compiling Qt for embedded use, are C++11 compilers always
>> available?
>Yes, of course. Embedded targets use GCC too.
>But that's not relevant to this discussion.
>> Personally I have avoided using latest  C++11 in my Qt applications.
>> My concern is that I will need to port a Qt app to an embedded platform
>> only has no C++11 compilers.  Or perhaps an old Linux distribution such
>> RHEL 5.
>RHEL 5 is already not supported and hasn't been since Qt 5.0. That's
>irrelevant for this discussion.
>Let me clarify what I said:
>> > We'd like to make Qt build unconditionally with the latest version of
>> > C++
>> > standard that is supported by the compiler.
>That means detecting what's supported and turning it on. I am not saying
>will stop supporting compilation in C++98 mode for compilers that don't
>support C++11. I meant that we will turn C++11 support unconditionally if
>compiler supports it.
>In other words, if you have GCC 4.4 or higher, you won't be able to
>compile Qt 
>in C++98 mode. The question is: why would you want to?

I think we should use the latest version of the standard that is supported
by the compiler by default (i.e. C++11 or C++14). Of course that excludes
versions of c++ that are still work in progress.

In addition, we have to ensure you can still compile Qt in C++98 mode for
the moment, so before turning this on, we need to make sure we have a
configuration in the CI system that tests Qt in C++98 mode.


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