42 lines
1020 B
C++
42 lines
1020 B
C++
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#pragma once
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#include <optional>
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#include <react/renderer/css/CSSDataType.h>
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namespace facebook::react {
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/**
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* The value <zero> represents a literal number with the value 0. Expressions
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* that merely evaluate to a <number> with the value 0 (for example, calc(0)) do
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* not match <zero>; only literal <number-token>s do.
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*
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* https://www.w3.org/TR/css-values-4/#zero-value
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*/
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struct CSSZero {
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constexpr bool operator==(const CSSZero& rhs) const = default;
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};
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template <>
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struct CSSDataTypeParser<CSSZero> {
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static constexpr auto consumePreservedToken(const CSSPreservedToken& token)
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-> std::optional<CSSZero> {
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if (token.type() == CSSTokenType::Number && token.numericValue() == 0) {
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return CSSZero{};
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}
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return {};
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}
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};
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static_assert(CSSDataType<CSSZero>);
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} // namespace facebook::react
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