28 Algorithms library [algorithms]

28.7 Sorting and related operations [alg.sorting]

28.7.3 Binary search [alg.binary.search]

28.7.3.4 binary_­search [binary.search]

template<class ForwardIterator, class T> constexpr bool binary_search(ForwardIterator first, ForwardIterator last, const T& value); template<class ForwardIterator, class T, class Compare> constexpr bool binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
Requires: The elements e of [first, last) shall be partitioned with respect to the expressions e < value and !(value < e) or comp(e, value) and !comp(value, e).
Also, for all elements e of [first, last), e < value shall imply !(value < e) or comp(e, value) shall imply !comp(value, e).
Returns: true if there is an iterator i in the range [first, last) that satisfies the corresponding conditions: !(*i < value) && !(value < *i) or comp(*i, value) == false && comp(value, *i) == false.
Complexity: At most comparisons.