How can I make changes to the effective qmake call?

[A Former User]

Hi! You can add CONFIG += c++14 to your *.pro file.

[jdent]

Ok, I added CONFIG += c++14 to my *.pro file, but now I am getting compiler errors like "/Users/juandent/Qt5.5.1/5.5/clang_64/lib/QtCore.framework/Headers/qstring.h:739: error: no type named 'u16string' in namespace 'std'
static inline QString fromStdU16String(const std::u16string &s);"
~~~~~^
in code like:

#if defined(Q_COMPILER_UNICODE_STRINGS) || defined(Q_QDOC)
static inline QString fromStdU16String(const std::u16string &s);
inline std::u16string toStdU16String() const;
static inline QString fromStdU32String(const std::u32string &s);
inline std::u32string toStdU32String() const;
#endif

?? This does not occur if I use CONFIG += c++11

Thanks,
Juan

[jdent]

What is strange about this error is that even if I #include<string>, the compiler complains that u16string does not exist in std namespace...

which is false!!
Is something corrupt??

Any ideas?
Juan

[SGaist]

Hi,

Are you running OS X ? What version of Qt ?

[jdent]

Hi,

Qt Creator version 3.5.1 (open source) based on Qt 5.5.1 (Clang 6.0 (Apple), 64 bit).

OS X version 10.11.2

Thanks,
Juan

[SGaist]

Also Qt 5.5.1 ? Or 5.6.0 Beta ?

Can you show your .pro file ?

[jdent]

Hi,

Yes Qt 5.5.1

The .pro is:

TEMPLATE = app
INCLUDEPATH += .

HEADERS = bookdelegate.h bookwindow.h initdb.h
RESOURCES = books.qrc
SOURCES = bookdelegate.cpp main.cpp bookwindow.cpp
FORMS = bookwindow.ui

CONFIG += c11
CONFIG += c++14

QT += sql widgets widgets

target.path = $$[QT_INSTALL_EXAMPLES]/sql/books
INSTALLS += target

wince {
CONFIG(debug, debug|release):sqlPlugins.files = $$QT_BUILD_TREE/plugins/sqldrivers/d4.dll
CONFIG(release, debug|release):sqlPlugins.files = $$QT_BUILD_TREE/plugins/sqldrivers/[^d]4.dll
sqlPlugins.path = sqldrivers
DEPLOYMENT += sqlPlugins
}

[SGaist]

It should be CONFIG += c++11

Also check that you are using the clang mkspec

[jdent]

Hi,

Yes with c++11 it works but I want to use c++14, and I know Xcode 7.2 supports c++14 ... since under the covers the compiler is doing the compiling, why can't I instruct it to work in C++ 14 mode?

What do you mean by clang mkspec? Where do I find that?

Thank you very much for your help so far!!
Juan

[SGaist]

Go to Qt Creator's preferences and take a look at the Kit, you should see there the mkspec. If empty look at the Qt Version used for the Kit but AFAIK, it should be clang by default.

[jdent]

what about using C++14? -- is it not possible?

Juan

[SGaist]

It should be yes. Usually only "CONFIG += c++14" should be enough.

[jdent]

Qt mkspec is empty but Qtversion is Qt 5.5.1 clang 64bit

?? Still have the problem

Thanks

[jdent]

Hi Qt Champ!

I found the answer finally!!

The solution is: IN ORDER to use C++14 you must also enable C++11, like so:

CONFIG+= c++11
CONFIG+= c++14

That solves all the problems!!

Thanks for the help!

Juan

[SGaist]

Great !

Then please mark the thread as solved using the "Topic Tool" button so other forum users may know a solution has been found :)