From d29a10c18933af05bd39a1c8ac968d9b7d565972 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A5rten=20Nordheim?= <marten.nordheim@qt.io>
Date: Wed, 21 Sep 2022 17:29:31 +0200
Subject: [PATCH] QFlags: Mark the operators declared in macro maybe_unused

Because, when used in a .cpp file, the compiler can verify that
they are. With warnings-are-errors this breaks compilation for me
on windows with clang++.

Change-Id: Ib29c3b0b485be2c7d7cf6f1fa4541cac8fe32708
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 2c6c76374eeb649f40787c840f9b4b38e5d48ccb)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/global/qflags.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index 92bcb0df9c0..c791c26ac1f 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -179,26 +179,35 @@ typedef QFlags<Enum> Flags;
 
 // These are opt-in, for backwards compatibility
 #define QT_DECLARE_TYPESAFE_OPERATORS_FOR_FLAGS_ENUM(Flags) \
+[[maybe_unused]] \
 constexpr inline Flags operator~(Flags::enum_type e) noexcept \
 { return ~Flags(e); } \
+[[maybe_unused]] \
 constexpr inline void operator|(Flags::enum_type f1, int f2) noexcept = delete;
 #else
 #define QT_DECLARE_TYPESAFE_OPERATORS_FOR_FLAGS_ENUM(Flags) \
+[[maybe_unused]] \
 constexpr inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) noexcept \
 { return QIncompatibleFlag(int(f1) | f2); }
 #endif
 
 #define Q_DECLARE_OPERATORS_FOR_FLAGS(Flags) \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) noexcept \
 { return QFlags<Flags::enum_type>(f1) | f2; } \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
 { return f2 | f1; } \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator&(Flags::enum_type f1, Flags::enum_type f2) noexcept \
 { return QFlags<Flags::enum_type>(f1) & f2; } \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator&(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
 { return f2 & f1; } \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator^(Flags::enum_type f1, Flags::enum_type f2) noexcept \
 { return QFlags<Flags::enum_type>(f1) ^ f2; } \
+[[maybe_unused]] \
 constexpr inline QFlags<Flags::enum_type> operator^(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
 { return f2 ^ f1; } \
 constexpr inline void operator+(Flags::enum_type f1, Flags::enum_type f2) noexcept = delete; \