From 49d94bbb41cede41ebe97004a84b2e3a4f5936e5 Mon Sep 17 00:00:00 2001
From: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>
Date: Thu, 30 Sep 2021 14:40:33 +0200
Subject: [PATCH] Assume that <variant> header is always present

This header is a C++17 feature that is already used unconditionally
in qtypeinfo.h.

Change-Id: I26330d298e95102f3e94c0c69fc95c1025666eb4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
---
 src/corelib/kernel/qvariant.h                       | 9 ---------
 tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp | 4 ----
 2 files changed, 13 deletions(-)

diff --git a/src/corelib/kernel/qvariant.h b/src/corelib/kernel/qvariant.h
index 213368a036b..bacaa44e95d 100644
--- a/src/corelib/kernel/qvariant.h
+++ b/src/corelib/kernel/qvariant.h
@@ -57,12 +57,7 @@
 #endif
 #include <memory>
 #include <type_traits>
-
-#if __has_include(<variant>)
 #include <variant>
-#elif defined(Q_CLANG_QDOC)
-namespace std { template<typename...> struct variant; }
-#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -402,7 +397,6 @@ class Q_CORE_EXPORT QVariant
         return QVariant(QMetaType::fromType<T>(), std::addressof(value));
     }
 
-#if __has_include(<variant>) || defined(Q_CLANG_QDOC)
     template<typename... Types>
     static inline QVariant fromStdVariant(const std::variant<Types...> &value)
     {
@@ -410,7 +404,6 @@ class Q_CORE_EXPORT QVariant
             return QVariant();
         return std::visit([](const auto &arg) { return fromValue(arg); }, value);
     }
-#endif
 
     template<typename T>
     bool canConvert() const
@@ -580,13 +573,11 @@ inline QVariant QVariant::fromValue(const QVariant &value)
     return value;
 }
 
-#if __has_include(<variant>)
 template<>
 inline QVariant QVariant::fromValue(const std::monostate &)
 {
     return QVariant();
 }
-#endif
 
 inline bool QVariant::isValid() const
 {
diff --git a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
index 40dfb79cff9..6166c8a639c 100644
--- a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
+++ b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
@@ -48,9 +48,7 @@
 #include <limits.h>
 #include <float.h>
 #include <cmath>
-#if __has_include(<variant>)
 #include <variant>
-#endif
 #include <QRegularExpression>
 #include <QDir>
 #include <QBuffer>
@@ -4882,7 +4880,6 @@ void tst_QVariant::shouldDeleteVariantDataWorksForAssociative()
 
 void tst_QVariant::fromStdVariant()
 {
-#if __has_include(<variant>)
     {
         typedef std::variant<int, bool> intorbool_t;
         intorbool_t stdvar = 5;
@@ -4913,7 +4910,6 @@ void tst_QVariant::fromStdVariant()
         QCOMPARE(qvar.type(), QVariant::Char);
         QCOMPARE(qvar.value<QChar>(), std::get<QChar>(stdvar));
     }
-#endif
 }
 
 void tst_QVariant::qt4UuidDataStream()