Qt 5.0 and c++11 with OSX Mountain Lion

Question

I'm giving c++ a try again after being away for 7 years. I've downloaded the newly released Qt 5.0 sdk for osx, but I can't get a basic c++11 feature compiled using Qt Creator. The following statement:

auto i = 3;

results in a compilation error:

mainwindow.cpp:19: error: ISO C++ forbids declaration of 'i' with no type

I've google around for similar problems and found suggestions to put

QMAKE_CXXFLAGS += -std=c++11
  or
CONFIG += c++11

in the .pro file. Unfortunately without success .The build fails on unrecognized command line options.

I must be doing something wrong. Any suggestions?

Thanks,

Frans

I've the latest version of xcode and the command line tools that come with it: version 4.5.2 (4G2008a). In Xcode itself, it's no problem to work with c++11 features. Also, building boost 1.52 did just work. — user1936348, Dec 29 '12 at 12:37
GCC 4.5 doesn't have a `c++11` standard mode, it has `c++0x` instead. — Mat, Dec 29 '12 at 12:45
Using c++0x in the .pro file in stead of c++11 shows the same problem unfortunately. — user1936348, Dec 29 '12 at 13:10
Did you ever get this sorted out? Same thing is happening to me. — Anthony, Jan 03 '13 at 15:50
http://stackoverflow.com/questions/11066068/how-to-program-c11-using-qt5 — Sadeq, Jan 04 '13 at 16:23
@ccSadegh: That's a different compiler on a different platform, and is the wrong solution for Xcode on the Mac. — Bob Murphy, Feb 18 '13 at 22:59

inkooboo · Answer 1 · 2013-04-02T09:37:18.460

3

It's looks like Qt Creator for Mac bug. I fixed it using

QMAKE_CXXFLAGS += -std=c++11 -stdlib=libc++ -mmacosx-version-min=10.7
LIBS += -stdlib=libc++ -mmacosx-version-min=10.7

in .pro file

edited Apr 02 '13 at 09:37

answered Apr 02 '13 at 08:35

inkooboo

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score 1 · Answer 2 · answered Jan 22 '15 at 14:47

I don't know if this is still an issue for you.

On my current system (Max OS X Yosemite - Qt 5.4 - QtCreator 3.0 - XCode 6.1.1) this works like a charm:

In .pro file:

macx {
    QMAKE_MACOSX_DEPLOYMENT_TARGET = 10.7
    QMAKE_CXXFLAGS += -mmacosx-version-min=10.7
    QMAKE_CFLAGS += -mmacosx-version-min=10.7
    QMAKE_MAC_SDK = macosx10.9
}

macx {
    QMAKE_CXXFLAGS += -std=c++11 -stdlib=libc++
    QMAKE_CFLAGS += -std=c++11 -stdlib=libc++
}
CONFIG += c++11

Make sure you have the latest Mac OS X SDK installed too.

score 0 · Answer 3 · answered Dec 30 '12 at 15:08

0

According to the gcc feature list, auto is supported since gcc 4.4through:

g++ -std=c++0x

you could also try the gcc-specific form:

g++ -std=gnu++0x

Maybe, in your case, an additional problem occurs (g++ parameters not correctly promoted to the compiler).

answered Dec 30 '12 at 15:08

rubber boots

14,924
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Thanks. No luck unfortunately. I suspect that the problem is related to the way the Qt 5.0 sdk for Mac is build (clang vs. g++). But I don't know enough about the XCode tools and/or Qt to proceed. I didn't find the Qt documentation helpful in this respect. – user1936348 Dec 30 '12 at 22:01

Qt 5.0 and c++11 with OSX Mountain Lion

3 Answers3

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