std::experimental::ranges::StrictTotallyOrdered, std::experimental::ranges::
Defined in header <experimental/ranges/concepts>
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||
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template
<
class T >
concept bool StrictTotallyOrdered =
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(1) | (ranges TS) |
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template
<
class T, class U >
concept bool StrictTotallyOrderedWith =
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(2) | (ranges TS) |
StrictTotallyOrdered<T> specifies that the comparison operators ==,!=,<,>,<=,>= on T yield results consistent with a strict total order on T.
StrictTotallyOrdered<T> is satisfied only if, given lvalues a, b and c of type
const
std::remove_reference_t
<T>
- Exactly one of bool(a < b), bool(a > b) and bool(a == b) is true
- If bool(a < b) and bool(b < c) are both true, then bool(a < c) is true
- bool (a > b) == bool (b < a)
- bool (a >= b) == ! bool (a < b)
- bool (a <= b) == ! bool (b < a)
StrictTotallyOrderedWith<T, U> specifies that the comparison operators ==,!=,<,>,<=,>= on (possibly mixed) T and U operands yield results consistent with a strict total order. Comparing mixed operands yields results equivalent to comparing the operands converted to their common type.
Formally, StrictTotallyOrderedWith<T, U> is satisfied only if, given any lvalue t of type
const
std::remove_reference_t
<T>
and any lvalue u of type
const
std::remove_reference_t
<U>
, and let C be
ranges::common_reference_t
<
const
std::remove_reference_t
<T>
&, const
std::remove_reference_t
<U>
&
>
- bool (t < u) == bool (C(t) < C(u) )
- bool (t > u) == bool (C(t) > C(u) )
- bool (t <= u) == bool (C(t) <= C(u) )
- bool (t >= u) == bool (C(t) >= C(u) )
- bool (u < t) == bool (C(u) < C(t) )
- bool (u > t) == bool (C(u) > C(t) )
- bool (u <= t) == bool (C(u) <= C(t) )
- bool (u >= t) == bool (C(u) >= C(t) )
Equality preservation
An expression is equality preserving if it results in equal outputs given equal inputs.
- The inputs to an expression consist of its operands.
- The outputs of an expression consist of its result and all operands modified by the expression (if any).
Every expression required to be equality preserving is further required to be stable
Unless noted otherwise, every expression used in a requires-expression
Implicit expression variations
A requires-expression implicit expression variations