std::indirect_equivalence_relation
| Defined in header <iterator>
|
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| template< class F, class I1, class I2 = I1 > concept indirect_equivalence_relation = |
(since C++20) | |
The concept indirect_equivalence_relation specifies requirements for algorithms that call equivalence relations as their arguments. The key difference between this concept and std::equivalence_relation is that it is applied to the types that I1 and I2 references, rather than I1 and I2 themselves.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| P2609R3 | C++20 | some requirements were defined in terms of std::iter_value_t<I>& which mishandled projections resulting in incompatibility with equivalence relation F& |
defined in terms of /*indirect-value-t*/<I> to correctly handle such projections |
| P2997R1 | C++20 | indirect_equivalence_relation required F& to satisfy equivalence_relation withstd::iter_common_reference_t<I> |
does not require |