[SOLVED] QT 5.2.0: Q_DECLARE_METATYPE requires value_type and other sequential class attributes to be defined
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I have a code that compiles and runs fine under QT 5.1.1. After upgrading to QT 5.2.0, I got errors:
@
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1372) : error C2039: 'value_type' : is not a member of 'MyTemplateClass<T>'
with
[
T=float
]
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1578) : see reference to class template instantiation 'QtPrivate::SequentialContainerConverterHelper<T>' being compiled
with
[
T=MyTemplateClassFlt
]
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1600) : see reference to function template instantiation 'int qRegisterNormalizedMetaType<T>(const QByteArray &,T *,QtPrivate::MetaTypeDefinedHelper<T,defined>::DefinedType)' being compiled
with
[
T=MyTemplateClassFlt,
defined=true
]
d:\users\vlad\vsprojects\qt\cmpt\libcc\libcct\MyTemplateClass.h(736) : see reference to function template instantiation 'int qRegisterMetaType<MyTemplateClassFlt>(const char *,T *,QtPrivate::MetaTypeDefinedHelper<T,defined>::DefinedType)' being compiled
with
[
T=MyTemplateClassFlt,
defined=true
]
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1372) : error C2146: syntax error : missing ',' before identifier 'value_type'
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1372) : error C2065: 'value_type' : undeclared identifier
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1382) : error C2955: 'QMetaTypeId2' : use of class template requires template argument list
c:\qt\qt5.2.0\5.2.0\msvc2012_64\include\qtcore\qmetatype.h(1479) : see declaration of 'QMetaTypeId2'@
These errors are generated from the line:
@
typedef MyTemplateClass<float> MyTemplateClassFlt; Q_DECLARE_METATYPE(MyTemplateClassFlt)
@MyTemplateClass is a simple template class which is not based on a sequential container. Why 5.2.0's Q_DECLARE_METATYPE now requires "T::value_type" and other attributes of sequential classes?
Is this a bug on 5.2.0 or my code is implicitly broken with undetectable under 5.1.1 problems?
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To leave this thread with an answer, it appeared that I was using Q_DECLARE_METATYPE_TEMPLATE_1ARG macro, which came quite handy to me, but that macro is not documented in QT and they changed its behavior, starting from 5.2.0.
