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Test the overflow check of json_view at the largest double

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Numbers of more than 19 digits at the boundary of the largest double
are decided by the locale-aware fallback of the overflow check.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
This commit is contained in:
Niels Lohmann
2026-09-29 02:41:44 +02:00
parent ea5a1caf28
commit 6d479d13ce
1 changed files with 11 additions and 0 deletions
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11
tests/src/unit-json_view_builder.cpp
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@@ -227,6 +227,17 @@ TEST_CASE("json_view builder")
{
check_same(text);
}
// the midpoint between the largest double and 2^1024 rounds to
// infinity (an overflow), one less to the largest double: with more
// than 19 digits, the fast conversions cannot decide these, and the
// overflow check falls back to strtod
const std::string midpoint = "179769313486231580793728971405303415079934132710037826936173778980444968292764750946649017977587207096330286416692887910946555547851940402630657488671505820681908902000708383676273854845817711531764475730270069855571366959622842914819860834936475292719074168444365510704342711559699508093042880177904174497792";
const std::string below = "179769313486231580793728971405303415079934132710037826936173778980444968292764750946649017977587207096330286416692887910946555547851940402630657488671505820681908902000708383676273854845817711531764475730270069855571366959622842914819860834936475292719074168444365510704342711559699508093042880177904174497791";
check_same(midpoint);
check_same("-" + midpoint);
check_same(below);
check_same("[" + below + "," + midpoint + "]");
}
SECTION("malformed input")