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87 lines
2.1 KiB
C++
87 lines
2.1 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_IntegerTypeTraits_h
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#define mozilla_IntegerTypeTraits_h
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#include <stddef.h>
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#include <stdint.h>
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#include <type_traits>
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namespace mozilla {
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namespace detail {
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/**
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* StdintTypeForSizeAndSignedness returns the stdint integer type
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* of given size (can be 1, 2, 4 or 8) and given signedness
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* (false means unsigned, true means signed).
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*/
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template <size_t Size, bool Signedness>
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struct StdintTypeForSizeAndSignedness;
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template <>
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struct StdintTypeForSizeAndSignedness<1, true> {
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typedef int8_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<1, false> {
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typedef uint8_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<2, true> {
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typedef int16_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<2, false> {
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typedef uint16_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<4, true> {
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typedef int32_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<4, false> {
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typedef uint32_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<8, true> {
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typedef int64_t Type;
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};
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template <>
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struct StdintTypeForSizeAndSignedness<8, false> {
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typedef uint64_t Type;
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};
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} // namespace detail
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template <size_t Size>
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struct UnsignedStdintTypeForSize
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: detail::StdintTypeForSizeAndSignedness<Size, false> {};
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template <size_t Size>
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struct SignedStdintTypeForSize
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: detail::StdintTypeForSizeAndSignedness<Size, true> {};
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template <typename IntegerType>
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struct PositionOfSignBit {
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static_assert(std::is_integral_v<IntegerType>,
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"PositionOfSignBit is only for integral types");
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// 8 here should be CHAR_BIT from limits.h, but the world has moved on.
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static const size_t value = 8 * sizeof(IntegerType) - 1;
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};
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} // namespace mozilla
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#endif // mozilla_IntegerTypeTraits_h
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