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Author SHA1 Message Date
Niels Lohmann 4776b9091c Fix astyle indentation of #include inside #ifdef in unit-items-cpp17.cpp
This repo's astyle style keeps preprocessor directives at column 0
even inside #ifdef blocks. The new tests/src/unit-items-cpp17.cpp
had its #include <map>/#include <string> indented, which made the
'check' CI job's amalgamation/formatting diff non-empty and failed
the aggregate check.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-06 11:29:33 +02:00
Niels Lohmann fd0ca40ea6 Extract C++17-only content from unit-items.cpp into its own test file
unit-items.cpp is a 1433-line file that was being compiled twice per
CI configuration (once for C++11, once for C++17) purely because it
contained a single, small JSON_HAS_CPP_17-gated SECTION ("structured
bindings", 14 lines). Move that SECTION into a new, dedicated file
(tests/src/unit-items-cpp17.cpp) so only that tiny file needs a
second build; unit-items.cpp itself now builds/tests only once. No
tests/CMakeLists.txt changes are needed since the existing
file(GLOB ... src/unit-*.cpp) plus json_test_add_test_for() already
auto-register and standard-gate any new unit-*.cpp file based on
whether it textually contains JSON_HAS_CPP_<N> (the same mechanism
already used for the existing unit-iterators3.cpp file, which follows
the identical pattern).

Verified with plain clang++ under -std=c++11/14/17/20 and via a local
CMake configure+build that:
- unit-items.cpp now only produces a test-items_cpp11 target (the
  former test-items_cpp17 target is gone) and its assertion/test-case
  counts are unchanged (2 test cases / 222 assertions) for every
  standard.
- The new unit-items-cpp17.cpp produces test-items-cpp17_cpp11 (an
  intentionally empty translation unit under C++11 that reports 0
  tests, 0 assertions, SUCCESS) and test-items-cpp17_cpp17 (1 test
  case / 1 assertion, identical to what "structured bindings" ran
  as before it was moved).

Separately, unit-regression1.cpp (1530 lines) was also being built
twice per CI configuration because it contained the substring
JSON_HAS_CPP_17 -- but on inspection this was dead code: an orphaned
"#ifdef JSON_HAS_CPP_17 / #include <variant> / #endif" left over from
when the actual std::variant-based regression test (issue #1292) was
relocated to unit-regression2.cpp. Nothing in unit-regression1.cpp
uses <variant>, so there is no SECTION/TEST_CASE to preserve here;
the dead include is simply removed. This was verified by grepping the
file for any other use of "variant" (none) and confirming issue #1292
is still covered by unit-regression2.cpp. Compiled and ran under
-std=c++11/14/17/20 and via CMake: unit-regression1.cpp now only
produces a test-regression1_cpp11 target (test-regression1_cpp17 is
gone) with an unchanged test-case count (3) under every standard.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-05 20:55:44 +02:00
8 changed files with 58 additions and 252 deletions
+1 -61
View File
@@ -149,11 +149,10 @@ class lexer : public lexer_base<BasicJsonType>
public:
using token_type = typename lexer_base<BasicJsonType>::token_type;
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false, bool discard_number_values_ = false) noexcept
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false) noexcept
: ia(std::move(adapter))
, ignore_comments(ignore_comments_)
, decimal_point_char(static_cast<char_int_type>(get_decimal_point()))
, discard_number_values(discard_number_values_)
{}
// deleted because of pointer members
@@ -1280,58 +1279,6 @@ scan_number_done:
// we are done scanning a number)
unget();
// If the caller does not need the converted value (only whether the
// input is syntactically valid; see json_sax_acceptor/accept()), an
// unsigned/integer token can be reported without calling
// strtoull()/strtoll() at all, *provided* we can already tell from
// the digit count alone that the conversion cannot overflow 64 bits.
// Such tokens are always finite and are accepted unconditionally by
// the parser regardless of their actual value (parser::sax_parse_internal()
// never checks finiteness for value_unsigned/value_integer), so the
// classification below is all that is needed.
//
// A decimal number with up to 18 digits is always representable in
// both std::uint64_t and std::int64_t (18 nines is ~1e18, well below
// both UINT64_MAX ~1.8e19 and INT64_MAX ~9.2e18), so strtoull()/strtoll()
// could not have set errno to ERANGE for it. Numbers with more digits
// (rare in practice) fall through to the exact code below, unchanged,
// so their handling -- including reclassification to value_float when
// the value overflows 64 bits, and rejection when it is not even
// finite as a double -- is bit-for-bit identical to before this
// optimization.
//
// Note this reasons about std::uint64_t/std::int64_t, not about
// number_unsigned_t/number_integer_t (BasicJsonType's own, possibly
// narrower, template parameters -- e.g. std::uint32_t). That is fine
// *only* because discard_number_values is exclusively set by
// accept() (see json.hpp), and accept() always parses through the
// library's own json_sax_acceptor -- never a user-supplied SAX
// consumer -- whose number_unsigned()/number_integer()/number_float()
// callbacks unconditionally discard their argument and return true.
// So for every caller that can reach this branch, neither the token
// classification below nor the eventual (possibly narrowed, and on
// this fast path left stale/unset) value_unsigned/value_integer is
// ever consulted -- an unsigned/integer token is accepted outright,
// and even a >18-digit token that this fast path deliberately falls
// through for is, once reclassified to value_float, still finite
// (and thus accepted) for any digit count that fits in number_unsigned_t
// or number_integer_t regardless of that type's width. If this
// function is ever taught to run with discard_number_values true for
// a caller that *does* read the converted value, this reasoning (and
// the fast path below) would need to be revisited.
if (discard_number_values)
{
constexpr std::size_t safe_digit_count = 18;
if (number_type == token_type::value_unsigned && token_buffer.size() <= safe_digit_count)
{
return token_type::value_unsigned;
}
if (number_type == token_type::value_integer && token_buffer.size() - 1 <= safe_digit_count)
{
return token_type::value_integer;
}
}
char* endptr = nullptr; // NOLINT(misc-const-correctness,cppcoreguidelines-pro-type-vararg,hicpp-vararg)
errno = 0;
@@ -1807,13 +1754,6 @@ scan_number_done:
const char_int_type decimal_point_char = '.';
/// the position of the decimal point in the input
std::size_t decimal_point_position = std::string::npos;
/// whether the caller (e.g. accept()/json_sax_acceptor) only needs the
/// token classification and never looks at the converted numeric value;
/// when set, scan_number() may skip strtoull()/strtoll() for
/// value_unsigned/value_integer tokens whose digit count guarantees they
/// fit into 64 bits (see scan_number())
const bool discard_number_values = false;
};
} // namespace detail
+2 -3
View File
@@ -72,10 +72,9 @@ class parser
parser_callback_t<BasicJsonType> cb = nullptr,
const bool allow_exceptions_ = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas_ = false,
const bool discard_number_values_ = false)
const bool ignore_trailing_commas_ = false)
: callback(std::move(cb))
, m_lexer(std::move(adapter), ignore_comments, discard_number_values_)
, m_lexer(std::move(adapter), ignore_comments)
, allow_exceptions(allow_exceptions_)
, ignore_trailing_commas(ignore_trailing_commas_)
{
+5 -6
View File
@@ -164,12 +164,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
detail::parser_callback_t<basic_json>cb = nullptr,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false,
const bool discard_number_values = false
const bool ignore_trailing_commas = false
)
{
return ::nlohmann::detail::parser<basic_json, InputAdapterType>(std::move(adapter),
std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas, discard_number_values);
std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
}
private:
@@ -4134,7 +4133,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(detail::input_adapter(std::forward<InputType>(i)), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(detail::input_adapter(std::forward<InputType>(i)), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
/// @brief check if the input is valid JSON (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -4145,7 +4144,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(detail::input_adapter(std::move(first), std::move(last)), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(detail::input_adapter(std::move(first), std::move(last)), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
JSON_HEDLEY_WARN_UNUSED_RESULT
@@ -4154,7 +4153,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
/// @brief generate SAX events
+8 -70
View File
@@ -7932,11 +7932,10 @@ class lexer : public lexer_base<BasicJsonType>
public:
using token_type = typename lexer_base<BasicJsonType>::token_type;
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false, bool discard_number_values_ = false) noexcept
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false) noexcept
: ia(std::move(adapter))
, ignore_comments(ignore_comments_)
, decimal_point_char(static_cast<char_int_type>(get_decimal_point()))
, discard_number_values(discard_number_values_)
{}
// deleted because of pointer members
@@ -9063,58 +9062,6 @@ scan_number_done:
// we are done scanning a number)
unget();
// If the caller does not need the converted value (only whether the
// input is syntactically valid; see json_sax_acceptor/accept()), an
// unsigned/integer token can be reported without calling
// strtoull()/strtoll() at all, *provided* we can already tell from
// the digit count alone that the conversion cannot overflow 64 bits.
// Such tokens are always finite and are accepted unconditionally by
// the parser regardless of their actual value (parser::sax_parse_internal()
// never checks finiteness for value_unsigned/value_integer), so the
// classification below is all that is needed.
//
// A decimal number with up to 18 digits is always representable in
// both std::uint64_t and std::int64_t (18 nines is ~1e18, well below
// both UINT64_MAX ~1.8e19 and INT64_MAX ~9.2e18), so strtoull()/strtoll()
// could not have set errno to ERANGE for it. Numbers with more digits
// (rare in practice) fall through to the exact code below, unchanged,
// so their handling -- including reclassification to value_float when
// the value overflows 64 bits, and rejection when it is not even
// finite as a double -- is bit-for-bit identical to before this
// optimization.
//
// Note this reasons about std::uint64_t/std::int64_t, not about
// number_unsigned_t/number_integer_t (BasicJsonType's own, possibly
// narrower, template parameters -- e.g. std::uint32_t). That is fine
// *only* because discard_number_values is exclusively set by
// accept() (see json.hpp), and accept() always parses through the
// library's own json_sax_acceptor -- never a user-supplied SAX
// consumer -- whose number_unsigned()/number_integer()/number_float()
// callbacks unconditionally discard their argument and return true.
// So for every caller that can reach this branch, neither the token
// classification below nor the eventual (possibly narrowed, and on
// this fast path left stale/unset) value_unsigned/value_integer is
// ever consulted -- an unsigned/integer token is accepted outright,
// and even a >18-digit token that this fast path deliberately falls
// through for is, once reclassified to value_float, still finite
// (and thus accepted) for any digit count that fits in number_unsigned_t
// or number_integer_t regardless of that type's width. If this
// function is ever taught to run with discard_number_values true for
// a caller that *does* read the converted value, this reasoning (and
// the fast path below) would need to be revisited.
if (discard_number_values)
{
constexpr std::size_t safe_digit_count = 18;
if (number_type == token_type::value_unsigned && token_buffer.size() <= safe_digit_count)
{
return token_type::value_unsigned;
}
if (number_type == token_type::value_integer && token_buffer.size() - 1 <= safe_digit_count)
{
return token_type::value_integer;
}
}
char* endptr = nullptr; // NOLINT(misc-const-correctness,cppcoreguidelines-pro-type-vararg,hicpp-vararg)
errno = 0;
@@ -9590,13 +9537,6 @@ scan_number_done:
const char_int_type decimal_point_char = '.';
/// the position of the decimal point in the input
std::size_t decimal_point_position = std::string::npos;
/// whether the caller (e.g. accept()/json_sax_acceptor) only needs the
/// token classification and never looks at the converted numeric value;
/// when set, scan_number() may skip strtoull()/strtoll() for
/// value_unsigned/value_integer tokens whose digit count guarantees they
/// fit into 64 bits (see scan_number())
const bool discard_number_values = false;
};
} // namespace detail
@@ -14103,10 +14043,9 @@ class parser
parser_callback_t<BasicJsonType> cb = nullptr,
const bool allow_exceptions_ = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas_ = false,
const bool discard_number_values_ = false)
const bool ignore_trailing_commas_ = false)
: callback(std::move(cb))
, m_lexer(std::move(adapter), ignore_comments, discard_number_values_)
, m_lexer(std::move(adapter), ignore_comments)
, allow_exceptions(allow_exceptions_)
, ignore_trailing_commas(ignore_trailing_commas_)
{
@@ -21653,12 +21592,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
detail::parser_callback_t<basic_json>cb = nullptr,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false,
const bool discard_number_values = false
const bool ignore_trailing_commas = false
)
{
return ::nlohmann::detail::parser<basic_json, InputAdapterType>(std::move(adapter),
std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas, discard_number_values);
std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
}
private:
@@ -25623,7 +25561,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(detail::input_adapter(std::forward<InputType>(i)), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(detail::input_adapter(std::forward<InputType>(i)), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
/// @brief check if the input is valid JSON (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -25634,7 +25572,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(detail::input_adapter(std::move(first), std::move(last)), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(detail::input_adapter(std::move(first), std::move(last)), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
JSON_HEDLEY_WARN_UNUSED_RESULT
@@ -25643,7 +25581,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
const bool ignore_comments = false,
const bool ignore_trailing_commas = false)
{
return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas).accept(true);
}
/// @brief generate SAX events
-92
View File
@@ -930,98 +930,6 @@ TEST_CASE("parser class")
CHECK(accept_helper("+1") == false);
CHECK(accept_helper("+0") == false);
}
SECTION("issue #5411 - skip conversion when accept() does not need the numeric value")
{
// lexer::scan_number() may skip strtoull()/strtoll() for
// value_unsigned/value_integer tokens when the caller (e.g.
// json::accept()) does not need the converted value, as long
// as the digit count alone guarantees no 64-bit overflow (see
// the "safe_digit_count" fast path in scan_number()). This
// differential test checks that json::accept() (which enables
// the fast path) and json::parse() (which never does) always
// agree, over a corpus that exercises both the fast path
// (<=18 digits) and the untouched, exact fallback path (>=19
// digits) -- including reclassification of huge digit-only
// integers to a (possibly non-finite) floating-point value.
const std::vector<std::pair<std::string, bool>> cases =
{
// normal small/large integers, both signs
{"0", true}, {"1", true}, {"-1", true}, {"42", true}, {"-42", true},
{"123456789", true}, {"-123456789", true},
// digit-count boundary around the 18-digit safe cutoff (both signs)
{std::string(17, '9'), true},
{std::string(18, '9'), true},
{std::string(19, '9'), true},
{std::string(20, '9'), true},
{"-" + std::string(17, '9'), true},
{"-" + std::string(18, '9'), true},
{"-" + std::string(19, '9'), true},
{"-" + std::string(20, '9'), true},
// 64-bit boundaries
{"9223372036854775807", true}, // INT64_MAX
{"-9223372036854775808", true}, // INT64_MIN
{"18446744073709551615", true}, // UINT64_MAX
{"18446744073709551616", true}, // UINT64_MAX + 1 (overflows uint64_t, finite double)
// the 28-digit example from the issue: overflows uint64_t
// but is finite as a double, so the scanner reclassifies
// it to value_float and it is accepted
{"9999999999999999999999999999", true},
// huge digit-only integers that overflow even a double -> rejected
{std::string(309, '9'), false},
{std::string(400, '9'), false},
{"1" + std::string(400, '0'), false},
// 1e999 / 1e400 style overflow -> rejected
{"1e999", false},
{"1e400", false},
{"-1e999", false},
{"1E999", false},
// values straddling DBL_MAX
{"1.7976931348623157e308", true}, // <= DBL_MAX, finite
{"1.7976931348623159e308", false}, // > DBL_MAX, overflows to inf
// a mix of other valid/invalid numeric syntax
{"3.14159", true},
{"-0.0", true},
{"1.0e10", true},
{"01", false},
{"-", false},
{"1.", false},
{"1e", false},
{"+1", false},
};
for (const auto& c : cases)
{
const std::string& number = c.first;
const bool expected = c.second;
CAPTURE(number)
CAPTURE(expected)
// accept() takes the fast path (skips conversion when possible)
CHECK(json::accept(number) == expected);
// parse() always performs the full conversion; it must agree
json j;
CHECK_NOTHROW(json::parser(nlohmann::detail::input_adapter(number), nullptr, false).parse(true, j));
CHECK(!j.is_discarded() == expected);
// wrap in an array so get_token() is exercised beyond the
// very first (constructor-time) scan as well
std::string wrapped = "[";
wrapped += number;
wrapped += ",";
wrapped += number;
wrapped += "]";
CHECK(json::accept(wrapped) == expected);
}
}
}
}
+42
View File
@@ -0,0 +1,42 @@
// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++ (supporting code)
// | | |__ | | | | | | version 3.12.0
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
// This file contains the C++17-only part of unit-items.cpp (structured
// bindings support for json::items()). It is kept in a separate
// translation unit so the (much larger) unit-items.cpp does not need to
// be compiled a second time just for this one SECTION.
#include "doctest_compatibility.h"
#include <nlohmann/json.hpp>
using nlohmann::json;
#ifdef JSON_HAS_CPP_17
#include <map>
#include <string>
TEST_CASE("items()")
{
SECTION("object")
{
SECTION("structured bindings")
{
json j = { {"A", 1}, {"B", 2} };
std::map<std::string, int> m;
for (auto const&[key, value] : j.items())
{
m.emplace(key, value);
}
CHECK(j.get<decltype(m)>() == m);
}
}
}
#endif
-16
View File
@@ -862,22 +862,6 @@ TEST_CASE("items()")
CHECK(counter == 3);
}
#ifdef JSON_HAS_CPP_17
SECTION("structured bindings")
{
json j = { {"A", 1}, {"B", 2} };
std::map<std::string, int> m;
for (auto const&[key, value] : j.items())
{
m.emplace(key, value);
}
CHECK(j.get<decltype(m)>() == m);
}
#endif
}
SECTION("const object")
-4
View File
@@ -30,10 +30,6 @@ using nlohmann::json;
#include <cstdio>
#include "make_test_data_available.hpp"
#ifdef JSON_HAS_CPP_17
#include <variant>
#endif
#include "fifo_map.hpp"
/////////////////////////////////////////////////////////////////////