diff options
Diffstat (limited to 'src/corelib')
| -rw-r--r-- | src/corelib/global/qtypetraits.h | 21 | ||||
| -rw-r--r-- | src/corelib/kernel/qmetatype.h | 2 |
2 files changed, 22 insertions, 1 deletions
diff --git a/src/corelib/global/qtypetraits.h b/src/corelib/global/qtypetraits.h index 3a305713e6..488e257e0f 100644 --- a/src/corelib/global/qtypetraits.h +++ b/src/corelib/global/qtypetraits.h @@ -506,6 +506,27 @@ Q_STATIC_ASSERT((!is_unsigned<qint64>::value)); Q_STATIC_ASSERT((!is_signed<quint64>::value)); Q_STATIC_ASSERT(( is_signed<qint64>::value)); +template<class T = void> struct is_default_constructible; + +template<> struct is_default_constructible<void> +{ +protected: + template<bool> struct test { typedef char type; }; +public: + static bool const value = false; +}; +template<> struct is_default_constructible<>::test<true> { typedef double type; }; + +template<class T> struct is_default_constructible : is_default_constructible<> +{ +private: + template<class U> static typename test<!!sizeof(::new U())>::type sfinae(U*); + template<class U> static char sfinae(...); +public: + static bool const value = sizeof(sfinae<T>(0)) > 1; +}; + + } // namespace QtPrivate QT_END_NAMESPACE diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h index 9ad8702e79..1b214e9f74 100644 --- a/src/corelib/kernel/qmetatype.h +++ b/src/corelib/kernel/qmetatype.h @@ -1773,7 +1773,7 @@ template <typename T> struct QMetaTypeIdQObject<T, QMetaType::IsGadget> { enum { - Defined = 1 + Defined = QtPrivate::is_default_constructible<T>::value }; static int qt_metatype_id() |