[alg.req.ind.cmp]

# 24 Iterators library [[iterators]](./#iterators)

## 24.3 Iterator requirements [[iterator.requirements]](iterator.requirements#alg.req.ind.cmp)

### 24.3.7 Common algorithm requirements [[alg.req]](alg.req#ind.cmp)

#### 24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iterators.tex#L2677)

The [indirectly_comparable](#concept:indirectly_comparable "24.3.7.5 Concept indirectly_­comparable [alg.req.ind.cmp]") concept specifies
the common requirements of algorithms that
compare values from two different sequences[.](#1.sentence-1)

template<class I1, class I2, class R, class P1 = identity, class P2 = identity>concept [indirectly_comparable](#concept:indirectly_comparable "24.3.7.5 Concept indirectly_­comparable [alg.req.ind.cmp]") =[indirect_binary_predicate](indirectcallable.indirectinvocable#concept:indirect_binary_predicate "24.3.6.3 Indirect callables [indirectcallable.indirectinvocable]")<R, projected<I1, P1>, projected<I2, P2>>;