Extract header qoverload.h from qglobal.h

Task-number: QTBUG-99313
Change-Id: Id827f95b5aa5d4e0d57dcc1060a0746bcaa34db3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/CMakeLists.txt

@@ -62,6 +62,7 @@ qt_internal_add_module(Core
         global/qnativeinterface.h global/qnativeinterface_p.h
         global/qnumeric.cpp global/qnumeric.h global/qnumeric_p.h
         global/qoperatingsystemversion.cpp global/qoperatingsystemversion.h global/qoperatingsystemversion_p.h
+        global/qoverload.h
         global/qprocessordetection.h
         global/qrandom.cpp global/qrandom.h global/qrandom_p.h
         global/qsysinfo.h

src/corelib/global/qglobal.cpp

@@ -1217,57 +1217,6 @@ static_assert(sizeof(qint64) == 8, "Internal error, qint64 is misdefined");
     \sa qMin(), qMax()
 */
 
-/*! \fn template <typename T> auto qOverload(T functionPointer)
-    \relates <QtGlobal>
-    \since 5.7
-
-    Returns a pointer to an overloaded function. The template
-    parameter is the list of the argument types of the function.
-    \a functionPointer is the pointer to the (member) function:
-
-    \snippet code/src_corelib_global_qglobal.cpp 52
-
-    If a member function is also const-overloaded \l qConstOverload and
-    \l qNonConstOverload need to be used.
-
-    qOverload() requires C++14 enabled. In C++11-only code, the helper
-    classes QOverload, QConstOverload, and QNonConstOverload can be used directly:
-
-    \snippet code/src_corelib_global_qglobal.cpp 53
-
-    \note Qt detects the necessary C++14 compiler support by way of the feature
-    test recommendations from
-    \l{https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations}
-    {C++ Committee's Standing Document 6}.
-
-    \sa qConstOverload(), qNonConstOverload(), {Differences between String-Based
-    and Functor-Based Connections}
-*/
-
-/*! \fn template <typename T> auto qConstOverload(T memberFunctionPointer)
-    \relates <QtGlobal>
-    \since 5.7
-
-    Returns the \a memberFunctionPointer pointer to a constant member function:
-
-    \snippet code/src_corelib_global_qglobal.cpp 54
-
-    \sa qOverload, qNonConstOverload, {Differences between String-Based
-    and Functor-Based Connections}
-*/
-
-/*! \fn template <typename T> auto qNonConstOverload(T memberFunctionPointer)
-    \relates <QtGlobal>
-    \since 5.7
-
-    Returns the \a memberFunctionPointer pointer to a non-constant member function:
-
-    \snippet code/src_corelib_global_qglobal.cpp 54
-
-    \sa qOverload, qNonConstOverload, {Differences between String-Based
-    and Functor-Based Connections}
-*/
-
 /*!
     \macro QT_VERSION_CHECK(major, minor, patch)
     \relates <QtGlobal>

src/corelib/global/qglobal.h

@@ -1213,62 +1213,6 @@ template <typename Ptr> inline auto qGetPtrHelper(Ptr &ptr) noexcept -> decltype
 #define Q_D(Class) Class##Private * const d = d_func()
 #define Q_Q(Class) Class * const q = q_func()
 
-#ifdef Q_QDOC
-// Just for documentation generation
-template<typename T>
-auto qOverload(T functionPointer);
-template<typename T>
-auto qConstOverload(T memberFunctionPointer);
-template<typename T>
-auto qNonConstOverload(T memberFunctionPointer);
-#else
-template <typename... Args>
-struct QNonConstOverload
-{
-    template <typename R, typename T>
-    constexpr auto operator()(R (T::*ptr)(Args...)) const noexcept -> decltype(ptr)
-    { return ptr; }
-
-    template <typename R, typename T>
-    static constexpr auto of(R (T::*ptr)(Args...)) noexcept -> decltype(ptr)
-    { return ptr; }
-};
-
-template <typename... Args>
-struct QConstOverload
-{
-    template <typename R, typename T>
-    constexpr auto operator()(R (T::*ptr)(Args...) const) const noexcept -> decltype(ptr)
-    { return ptr; }
-
-    template <typename R, typename T>
-    static constexpr auto of(R (T::*ptr)(Args...) const) noexcept -> decltype(ptr)
-    { return ptr; }
-};
-
-template <typename... Args>
-struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
-{
-    using QConstOverload<Args...>::of;
-    using QConstOverload<Args...>::operator();
-    using QNonConstOverload<Args...>::of;
-    using QNonConstOverload<Args...>::operator();
-
-    template <typename R>
-    constexpr auto operator()(R (*ptr)(Args...)) const noexcept -> decltype(ptr)
-    { return ptr; }
-
-    template <typename R>
-    static constexpr auto of(R (*ptr)(Args...)) noexcept -> decltype(ptr)
-    { return ptr; }
-};
-
-template <typename... Args> constexpr inline QOverload<Args...> qOverload = {};
-template <typename... Args> constexpr inline QConstOverload<Args...> qConstOverload = {};
-template <typename... Args> constexpr inline QNonConstOverload<Args...> qNonConstOverload = {};
-#endif
-
-
 class QByteArray;
 Q_CORE_EXPORT QByteArray qgetenv(const char *varName);
 // need it as two functions because QString is only forward-declared here
@@ -1290,13 +1234,6 @@ Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nu
          "Compile your code with -fPIC (and not with -fPIE)."
 #endif
 
-#define QT_VA_ARGS_CHOOSE(_1, _2, _3, _4, _5, _6, _7, _8, _9, N, ...) N
-#define QT_VA_ARGS_EXPAND(...) __VA_ARGS__ // Needed for MSVC
-#define QT_VA_ARGS_COUNT(...) QT_VA_ARGS_EXPAND(QT_VA_ARGS_CHOOSE(__VA_ARGS__, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
-#define QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC) MACRO##_##ARGC
-#define QT_OVERLOADED_MACRO_IMP(MACRO, ARGC) QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC)
-#define QT_OVERLOADED_MACRO(MACRO, ...) QT_VA_ARGS_EXPAND(QT_OVERLOADED_MACRO_IMP(MACRO, QT_VA_ARGS_COUNT(__VA_ARGS__))(__VA_ARGS__))
-
 // This macro can be used to calculate member offsets for types with a non standard layout.
 // It uses the fact that offsetof() is allowed to support those types since C++17 as an optional
 // feature. All our compilers do support this, but some issue a warning, so we wrap the offsetof()
@@ -1322,6 +1259,7 @@ QT_END_NAMESPACE
 #include <QtCore/qforeach.h>
 #include <QtCore/qglobalstatic.h>
 #include <QtCore/qnumeric.h>
+#include <QtCore/qoverload.h>
 #include <QtCore/qtranslation.h>
 #include <QtCore/qversiontagging.h>
 

src/corelib/global/qoverload.h

@@ -0,0 +1,75 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QOVERLOAD_H
+#define QOVERLOAD_H
+
+#if 0
+#pragma qt_class(QOverload)
+#pragma qt_sync_stop_processing
+#endif
+
+#ifdef Q_QDOC
+// Just for documentation generation
+template<typename T>
+auto qOverload(T functionPointer);
+template<typename T>
+auto qConstOverload(T memberFunctionPointer);
+template<typename T>
+auto qNonConstOverload(T memberFunctionPointer);
+#else
+template <typename... Args>
+struct QNonConstOverload
+{
+    template <typename R, typename T>
+    constexpr auto operator()(R (T::*ptr)(Args...)) const noexcept -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R, typename T>
+    static constexpr auto of(R (T::*ptr)(Args...)) noexcept -> decltype(ptr)
+    { return ptr; }
+};
+
+template <typename... Args>
+struct QConstOverload
+{
+    template <typename R, typename T>
+    constexpr auto operator()(R (T::*ptr)(Args...) const) const noexcept -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R, typename T>
+    static constexpr auto of(R (T::*ptr)(Args...) const) noexcept -> decltype(ptr)
+    { return ptr; }
+};
+
+template <typename... Args>
+struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
+{
+    using QConstOverload<Args...>::of;
+    using QConstOverload<Args...>::operator();
+    using QNonConstOverload<Args...>::of;
+    using QNonConstOverload<Args...>::operator();
+
+    template <typename R>
+    constexpr auto operator()(R (*ptr)(Args...)) const noexcept -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R>
+    static constexpr auto of(R (*ptr)(Args...)) noexcept -> decltype(ptr)
+    { return ptr; }
+};
+
+template <typename... Args> constexpr inline QOverload<Args...> qOverload = {};
+template <typename... Args> constexpr inline QConstOverload<Args...> qConstOverload = {};
+template <typename... Args> constexpr inline QNonConstOverload<Args...> qNonConstOverload = {};
+
+#endif // Q_QDOC
+
+#define QT_VA_ARGS_CHOOSE(_1, _2, _3, _4, _5, _6, _7, _8, _9, N, ...) N
+#define QT_VA_ARGS_EXPAND(...) __VA_ARGS__ // Needed for MSVC
+#define QT_VA_ARGS_COUNT(...) QT_VA_ARGS_EXPAND(QT_VA_ARGS_CHOOSE(__VA_ARGS__, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
+#define QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC) MACRO##_##ARGC
+#define QT_OVERLOADED_MACRO_IMP(MACRO, ARGC) QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC)
+#define QT_OVERLOADED_MACRO(MACRO, ...) QT_VA_ARGS_EXPAND(QT_OVERLOADED_MACRO_IMP(MACRO, QT_VA_ARGS_COUNT(__VA_ARGS__))(__VA_ARGS__))
+
+#endif /* QOVERLOAD_H */

src/corelib/global/qoverload.qdoc

@@ -0,0 +1,53 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
+
+/*! \fn template <typename T> auto qOverload(T functionPointer)
+    \relates <QOverload>
+    \since 5.7
+
+    Returns a pointer to an overloaded function. The template
+    parameter is the list of the argument types of the function.
+    \a functionPointer is the pointer to the (member) function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 52
+
+    If a member function is also const-overloaded \l qConstOverload and
+    \l qNonConstOverload need to be used.
+
+    qOverload() requires C++14 enabled. In C++11-only code, the helper
+    classes QOverload, QConstOverload, and QNonConstOverload can be used directly:
+
+    \snippet code/src_corelib_global_qglobal.cpp 53
+
+    \note Qt detects the necessary C++14 compiler support by way of the feature
+    test recommendations from
+    \l{https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations}
+    {C++ Committee's Standing Document 6}.
+
+    \sa qConstOverload(), qNonConstOverload(), {Differences between String-Based
+    and Functor-Based Connections}
+*/
+
+/*! \fn template <typename T> auto qConstOverload(T memberFunctionPointer)
+    \relates <QOverload>
+    \since 5.7
+
+    Returns the \a memberFunctionPointer pointer to a constant member function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 54
+
+    \sa qOverload, qNonConstOverload, {Differences between String-Based
+    and Functor-Based Connections}
+*/
+
+/*! \fn template <typename T> auto qNonConstOverload(T memberFunctionPointer)
+    \relates <QOverload>
+    \since 5.7
+
+    Returns the \a memberFunctionPointer pointer to a non-constant member function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 54
+
+    \sa qOverload, qNonConstOverload, {Differences between String-Based
+    and Functor-Based Connections}
+*/