diff options
Diffstat (limited to 'src/corelib/global/qglobal.h')
| -rw-r--r-- | src/corelib/global/qglobal.h | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h index 32176913ea..7a0804d436 100644 --- a/src/corelib/global/qglobal.h +++ b/src/corelib/global/qglobal.h @@ -44,6 +44,8 @@ #ifdef __cplusplus # include <type_traits> # include <cstddef> +# include <type_traits> +# include <utility> #endif #include <stddef.h> @@ -917,17 +919,34 @@ QT_WARNING_DISABLE_MSVC(4530) /* C++ exception handler used, but unwind semantic #ifndef QT_NO_FOREACH +namespace QtPrivate { + template <typename T> class QForeachContainer { QForeachContainer &operator=(const QForeachContainer &) Q_DECL_EQ_DELETE; public: QForeachContainer(const T &t) : c(t), i(c.begin()), e(c.end()) {} QForeachContainer(T &&t) : c(std::move(t)), i(c.begin()), e(c.end()) {} + QForeachContainer(const QForeachContainer &other) + : c(other.c), + i(c.begin()), + e(c.end()), + control(other.control) + { + } + const T c; typename T::const_iterator i, e; int control = 1; }; +template<typename T> +QForeachContainer<typename std::decay<T>::type> qMakeForeachContainer(T &&t) +{ + return QForeachContainer<typename std::decay<T>::type>(std::forward<T>(t)); +} + +} // Explanation of the control word: // - it's initialized to 1 // - that means both the inner and outer loops start @@ -938,7 +957,7 @@ public: // - if there was a break inside the inner loop, it will exit with control still // set to 1; in that case, the outer loop will invert it to 0 and will exit too #define Q_FOREACH(variable, container) \ -for (QForeachContainer<typename std::remove_reference<decltype(container)>::type> _container_((container)); \ +for (auto _container_ = QtPrivate::qMakeForeachContainer(container); \ _container_.control && _container_.i != _container_.e; \ ++_container_.i, _container_.control ^= 1) \ for (variable = *_container_.i; _container_.control; _container_.control = 0) |