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Correctly promote partial | promote(partial) #83

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Merged
yaito3014 merged 1 commit into from
May 22, 2025
Merged

Correctly promote partial | promote(partial) #83

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10 changes: 8 additions & 2 deletions include/yk/compare/comparator.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -280,8 +280,14 @@ struct promote_comparator : comparator_interface {
const auto res = std::invoke(comp1, x, y);

if constexpr (std::same_as<From, To>) {
if (res == From::equivalent) return std::invoke(comp2, x, y);
return res;
if constexpr (std::same_as<From, std::partial_ordering>) {
if (res == From::equivalent || res == From::unordered) return std::invoke(comp2, x, y);
return res;

} else {
if (res == From::equivalent) return std::invoke(comp2, x, y);
return res;
}

} else {
if (res == From::less) return To::less;
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20 changes: 17 additions & 3 deletions test/compare.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -434,17 +434,31 @@ BOOST_AUTO_TEST_CASE(ClosureTypeTraits)
}
}

struct PartialPartial
{
double a, b;
std::partial_ordering operator<=>(const PartialPartial&) const noexcept = default;
};

BOOST_AUTO_TEST_CASE(promotion)
{
using namespace yk::comparators;

constexpr double NaN = std::numeric_limits<double>::quiet_NaN();

// partial | promote(partial)
{
const auto partial_comparator = [](double a, double b) -> std::partial_ordering { return a <=> b; };

auto comp = partial_comparator | promote(partial_comparator);
BOOST_TEST((comp(3.14, 1.41) == std::partial_ordering::greater));
BOOST_TEST((comp(3.14, std::numeric_limits<double>::quiet_NaN()) == std::partial_ordering::unordered));
BOOST_TEST((comp(3.14, NaN) == std::partial_ordering::unordered));
}
{
auto comp = extract(&PartialPartial::a) | promote(extract(&PartialPartial::b));
BOOST_TEST((comp(PartialPartial{1.0, NaN}, PartialPartial{2.0, NaN}) == std::partial_ordering::less));
BOOST_TEST(((PartialPartial{NaN, 1.0} <=> PartialPartial{NaN, 2.0}) == std::partial_ordering::unordered));
BOOST_TEST((comp(PartialPartial{NaN, 1.0}, PartialPartial{NaN, 2.0}) == std::partial_ordering::less));
}

// partial | promote(weak)
Expand All @@ -454,7 +468,7 @@ BOOST_AUTO_TEST_CASE(promotion)

auto comp = partial_comparator | promote(weak_comparator);
BOOST_TEST((comp(3.14, 1.41) == std::weak_ordering::greater));
BOOST_TEST((comp(3.14, std::numeric_limits<double>::quiet_NaN()) == std::weak_ordering::less));
BOOST_TEST((comp(3.14, NaN) == std::weak_ordering::less));
}

// partial | promote(strong)
Expand All @@ -464,7 +478,7 @@ BOOST_AUTO_TEST_CASE(promotion)

auto comp = partial_comparator | promote(strong_comparator);
BOOST_TEST((comp(3.14, 1.41) == std::strong_ordering::greater));
BOOST_TEST((comp(3.14, std::numeric_limits<double>::quiet_NaN()) == std::strong_ordering::less));
BOOST_TEST((comp(3.14, NaN) == std::strong_ordering::less));
}

// weak | promote(weak)
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