std::experimental::ranges::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)
concept bool StrictWeakOrder = Relation<R, T, U>;
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,bandc, ifr(a, b)andr(b, c)are both true thenr(a, c)is true; - let
e(a, b)be!r(a, b) && !r(b, a), theneis transitive:e(a, b) && e(b, c)impliese(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.
[edit] Notes
The distinction between Relation and StrictWeakOrder is purely semantic.