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| Category: algorithms | | Component type: function |
Prototype
Is_sorted is an overloaded name; there are actually two is_sorted functions.
template <class ForwardIterator>
bool is_sorted(ForwardIterator first, ForwardIterator last)
template <class ForwardIterator, class StrictWeakOrdering>
bool is_sorted(ForwardIterator first, ForwardIterator last,
StrictWeakOrdering comp)
Description
Is_sorted returns true if the range [first, last) is sorted in ascending order, and false otherwise.
The two versions of is_sorted differ in how they define whether one element is less than another. The first version compares objects using operator<, and the second compares objects using the functors comp. The first version of is_sorted returns true if and only if, for every iterator i in the range [first, last - 1), *(i + 1) < *i is false. The second version returns true if and only if, for every iterator i in the range [first, last - 1), comp(*(i + 1), i) is false
Definition
Defined in algo.h.
Requirements on types
For the first version:
For the second version:
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ForwardIterator is a model of ForwardIterator.
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StrictWeakOrdering is a model of StrictWeakOrdering.
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ForwardIterator's value type is convertible to StrictWeakOrdering's argument type.
Preconditions
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[first, last) is a valid range.
Complexity
Linear. Zero comparisons if [first, last) is an empty range, otherwise at most (last - first) - 1 comparisons.
Example
int A[] = {1, 4, 2, 8, 5, 7};
const int N = sizeof(A) / sizeof(int);
assert(!is_sorted(A, A + N));
sort(A, A + N);
assert(is_sorted(A, A + N));
Notes
See also
sort, stable_sort, partial_sort, partial_sort_copy, sort_heap, binary_search, lower_bound, upper_bound, less<T>, StrictWeakOrdering, LessThanComparable
