std::experimental::ranges::mismatch - cppreference.com (original) (raw)

1. Returns the first mismatching pair of elements from two ranges: one defined by [first1, last1) and another defined by [first2, last2).

2. Same as (1), but uses r1 as the first source range and r2 as the second source range, as if using ranges::begin(r1) as first1, ranges::end(r1) as last1, ranges::begin(r2) as first2, and ranges::end(r2) as last2.

3. Same as (1), but behaves as if first2 is std::decay_t<I2> first2 = std::forward<I2>(first2_); and last2 is ranges::unreachable{}. The underlying algorithm never increments first2 more than last1 - first1 times.

4. Same as (3), but uses r1 as the first source range, as if using ranges::begin(r1) as first1 and ranges::end(r1) as last1.

Elements are compared using pred to the projected elements of the two ranges, as if by ranges::invoke(pred, ranges::invoke(proj1, *i), ranges::invoke(proj2, *j)).

Notwithstanding the declarations depicted above, the actual number and order of template parameters for algorithm declarations is unspecified. Thus, if explicit template arguments are used when calling an algorithm, the program is probably non-portable.

Contents

• 1 Parameters
• 2 Return value
• 3 Complexity
• 4 Possible implementation
• 5 Example
• 6 See also

[edit] Parameters

[edit] Return value

A tagged_pair object with iterators to the first two non-equal elements (the iterator from the first range has the tag in1 and the iterator from the second range has the tag in2).

If no mismatches are found when the comparison reaches last1 or last2, whichever happens first, the pair holds the end iterator and the corresponding iterator from the other range.

[edit] Complexity

At most last1 - first1 applications of the predicate and each projection.

[edit] Possible implementation

template<InputIterator I1, Sentinel S1, InputIterator I2, Sentinel S2, class Proj1 = ranges::identity, class Proj2 = ranges::identity, class Pred = ranges::equal_to<>> requires IndirectRelation<Pred, projected<I1, Proj1>, projected<I2, Proj2>> auto mismatch(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = Pred{}, Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}) -> ranges::tagged_pair<tag::in1(I1), tag::in2(I2)> { while (first1 != last1 && first2 != last2 && ranges::invoke(pred, ranges::invoke(proj1, *first1), ranges::invoke(proj2, *first2))) { ++first1; ++first2; } return {first1, first2}; }

[edit] Example

[edit] See also