std::experimental::ranges::StrictWeakOrder

 

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Same DerivedFrom ConvertibleTo	CommonReference Common	Integral SignedIntegral UnsignedIntegral	Assignable SwappableSwappableWith
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Destructible Constructible DefaultConstructible	MoveConstructible CopyConstructible	Movable Copyable	Semiregular Regular
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Boolean	WeaklyEqualityComparableWith	EqualityComparableEqualityComparableWith	StrictTotallyOrderedStrictTotallyOrderedWith
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InvocableRegularInvocable	Predicate	Relation	StrictWeakOrder
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Defined in header <experimental/ranges/concepts>
template< class R, class T, class U > concept bool StrictWeakOrder = Relation<R, T, U>;	(1)	(ranges TS)

The concept StrictWeakOrder<R, T, U> specifies that the Relation R imposes a strict weak ordering on its arguments. A relation r is a strict weak ordering if

• it is irreflexive: for all x, r(x, x) is false;
• it is transitive: for all a, b and c, if r(a, b) and r(b, c) are both true then r(a, c) is true;
• let e(a, b) be !r(a, b) && !r(b, a), then e is transitive: e(a, b) && e(b, c) implies e(a, c).

Under these conditions, it can be shown that e is an equivalence relation, and r induces a strict total ordering on the equivalence classes determined by e.

Notes

The distinction between Relation and StrictWeakOrder is purely semantic.