Category: algorithms | Component type: function |
template <class InputIterator1, class InputIterator2> bool equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2); template <class InputIterator1, class InputIterator2, class BinaryPredicate> bool equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, BinaryPredicate binary_pred);
The first version of equal returns true if and only if for every iterator i in [first1, last1), *i == *(first2 + (i - first1)). The second version of equal returns true if and only if for every iterator i in [first1, last1), binary_pred(*i, *(first2 + (i - first1)) is true.
int A1[] = { 3, 1, 4, 1, 5, 9, 3 }; int A2[] = { 3, 1, 4, 2, 8, 5, 7 }; const int N = sizeof(A1) / sizeof(int); cout << "Result of comparison: " << equal(A1, A1 + N, A2) << endl;
[1] Note that this is very similar to the behavior of mismatch: The only real difference is that while equal will simply return false if the two ranges differ, mismatch returns the first location where they do differ. The expression equal(f1, l1, f2) is precisely equivalent to the expression mismatch(f1, l1, f2).first == l1, and this is in fact how equal could be implemented.