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https://github.com/nlohmann/json.git
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Niels Lohmann
759dd2e1b1
Add json_document and json_view, a read-only, zero-copy index of a JSON text, as the first public slice of the zero-copy view (#5295). A parse produces a flat array of 16-byte nodes in document order, one per value and one per object key. Strings stay in the source text; escaped strings are decoded into an arena. Integers are converted while their digits are in the cache; floats keep only their digit layout and are converted on read. Containers store the size of their subtree, so a reader can step over one in constant time. A document makes a handful of allocations, however many values it has. The parser accepts exactly what json::parse accepts, with every combination of ignore_comments and ignore_trailing_commas, with and without a trailing NUL, and under JSON_STRICT_NUL_HANDLING. It is portable C++11 and does not depend on byte order. basic_json_document adds parse, parse_copy, accept, read (reuses a document's memory), root, is_discarded, source, owns_source, node_count, memory_usage, and shrink_to_fit. basic_json_view adds type, the is_* queries, operator bool, size, empty, materialize, and source_offset. A parse error throws the same exception basic_json::parse would throw for the same input, message and position included. detail::abi_config keeps JSON_STRICT_NUL_HANDLING and JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON readable after json.hpp undefines them, in the ABI namespace so they always match the basic_json in use. A NUL byte that ends a // comment is the end of the input, as in parse() since #5696. Signed-off-by: Niels Lohmann <mail@nlohmann.me>
35 lines
1.1 KiB
C++
35 lines
1.1 KiB
C++
// __ _____ _____ _____
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// __| | __| | | | JSON for Modern C++
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// | | |__ | | | | | | version 3.12.0
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// |_____|_____|_____|_|___| https://github.com/nlohmann/json
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//
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// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
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// SPDX-License-Identifier: MIT
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#pragma once
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#include <nlohmann/detail/abi_macros.hpp>
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NLOHMANN_JSON_NAMESPACE_BEGIN
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namespace detail
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{
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/*!
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@brief the configuration macros that change the library's behavior
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json.hpp undefines these macros at its end (see macro_unscope.hpp), so code
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that builds on the library after it (json_view.hpp) reads them here. Like the
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macros, they are part of the ABI namespace, so they always match the
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basic_json they are used with.
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*/
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struct abi_config
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{
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/// JSON_STRICT_NUL_HANDLING: a null byte is an error, not the end of input
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static constexpr bool strict_nul_handling = JSON_STRICT_NUL_HANDLING != 0;
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/// JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
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static constexpr bool legacy_discarded_value_comparison = JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON != 0;
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};
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} // namespace detail
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NLOHMANN_JSON_NAMESPACE_END
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