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Diffstat (limited to 'src/corelib/global/q20functional.h')
-rw-r--r-- | src/corelib/global/q20functional.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/src/corelib/global/q20functional.h b/src/corelib/global/q20functional.h new file mode 100644 index 0000000000..a39b4fceb3 --- /dev/null +++ b/src/corelib/global/q20functional.h @@ -0,0 +1,46 @@ +// Copyright (C) 2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com> +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only +#ifndef Q20FUNCTIONAL_H +#define Q20FUNCTIONAL_H + +#include <QtCore/qglobal.h> + +#include <functional> + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. Types and functions defined in this +// file can reliably be replaced by their std counterparts, once available. +// You may use these definitions in your own code, but be aware that we +// will remove them once Qt depends on the C++ version that supports +// them in namespace std. There will be NO deprecation warning, the +// definitions will JUST go away. +// +// If you can't agree to these terms, don't use these definitions! +// +// We mean it. +// + +#include <functional> + +QT_BEGIN_NAMESPACE + +namespace q20 { +// like std::identity +#ifdef __cpp_lib_ranges +using std::identity; +#else +struct identity +{ + struct is_transparent {}; + template <typename T> + constexpr T &&operator()(T&& t) const noexcept { return std::forward<T>(t); } +}; +#endif // __cpp_lib_ranges +} // namespace q20 + +QT_END_NAMESPACE + +#endif /* Q20FUNCTIONAL_H */ |