# 11 Algorithms library [algorithms]

## 11.3 Non-modifying sequence operations [alg.nonmodifying]

### 11.3.10 Mismatch [mismatch]

``` template <InputIterator I1, Sentinel<I1> S1, InputIterator I2, Sentinel<I2> S2, class Proj1 = identity, class Proj2 = identity, IndirectRelation<projected<I1, Proj1>, projected<I2, Proj2>> Pred = equal_to<>> tagged_pair<tag::in1(I1), tag::in2(I2)> mismatch(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = Pred{}, Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}); template <InputRange Rng1, InputRange Rng2, class Proj1 = identity, class Proj2 = identity, IndirectRelation<projected<iterator_t<Rng1>, Proj1>, projected<iterator_t<Rng2>, Proj2>> Pred = equal_to<>> tagged_pair<tag::in1(safe_iterator_t<Rng1>), tag::in2(safe_iterator_t<Rng2>)> mismatch(Rng1&& rng1, Rng2&& rng2, Pred pred = Pred{}, Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}); ```

Returns: A pair of iterators i and j such that j == first2 + (i - first1) and i is the first iterator in the range [first1,last1) for which the following corresponding conditions hold:

• j is in the range [first2, last2).

• *i != *(first2 + (i - first1))

• !invoke(pred, invoke(proj1, *i), invoke(proj2, *(first2 + (i - first1))))

Returns the pair first1 + min(last1 - first1, last2 - first2) and first2 + min(last1 - first1, last2 - first2) if such an iterator i is not found.

Complexity: At most last1 - first1 applications of the corresponding predicate and both projections.