path: root/src/corelib/global/q26numeric.h

// Copyright (C) 2024 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 Q26NUMERIC_H#define Q26NUMERIC_H#include <QtCore/qglobal.h>//// 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 <numeric>#include <limits>#include <type_traits> QT_BEGIN_NAMESPACE namespace q26 {// Like std::saturate_cast#ifdef __cpp_lib_saturation_arithmeticusingstd::saturate_cast;#elsetemplate<typename To, typename From>constexpr autosaturate_cast(From x){static_assert(std::is_integral_v<To>);static_assert(std::is_integral_v<From>);[[maybe_unused]]constexpr auto Lo = (std::numeric_limits<To>::min)();constexpr auto Hi = (std::numeric_limits<To>::max)();ifconstexpr(std::is_signed_v<From> ==std::is_signed_v<To>) {// same signedness, we can accept regular integer conversion rulesreturn x < Lo ? Lo : x > Hi ? Hi :/*else*/To(x);}else{ifconstexpr(std::is_signed_v<From>) {// ie. !is_signed_v<To>if(x < From{0})return To{0};}// from here on, x >= 0using FromU =std::make_unsigned_t<From>;using ToU =std::make_unsigned_t<To>;returnFromU(x) >ToU(Hi) ? Hi :To(x);// assumes Hi >= 0}}#endif// __cpp_lib_saturation_arithmetic}// namespace q26 QT_END_NAMESPACE #endif/* Q26NUMERIC_H */