C++ In a Nutshell

Name

mismatch function template — Finds first position where two ranges differ

Synopsis

template<typename InIter1, typename InIter2>
  pair<InIter1, InIter2>
    mismatch(InIter1 first1, InIter1 last1, InIter2 first2);
template<typename InIter1, typename InIter2, typename BinaryPredicate>
  pair<InIter1, InIter2>
    mismatch(InIter1 first1, InIter1 last1, InIter2 first2, 
             BinaryPredicate pred);

The mismatch function template compares two sequences pairwise and returns a pair of iterators that identifies the first elements at which the sequences differ. The first sequence is [first1, last1), and the second sequence starts at first2 and has at least as many elements as the first sequence.

The return value is a pair of iterators; the first member of the pair points to an element of the first sequence, and second member of the pair points to an element of the second sequence. The two iterators have the same offset within their respective ranges. If the two sequences are equivalent, the pair returned is last1 and an iterator that points to the second sequence at the same offset (let’s call it last2).

The first form compares items with the == operator. The second form calls pred(*iter1, *iter2).

Figure 13-8 illustrates how the mismatch function template works.

Figure 13-8. Checking two sequences for a mismatch

Technical Notes

The mismatch function template returns the pair (first1 + n, first2 + n), in which ...