Sprout/source/libs/algorithm/find_first_of.rst
2013-08-30 14:02:02 +09:00

62 lines
2.2 KiB
ReStructuredText

.. _sprout-algorithm-find:
###############################################################################
find_first_of
###############################################################################
Interface
========================================
.. sourcecode:: c++
template<typename InputIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR InputIterator1
find_first_of(
InputIterator1 first1, InputIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2
);
template<typename InputIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR InputIterator1
find_first_of(
InputIterator1 first1, InputIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred
);
Effects
========================================
| Finds an element that matches one of a set of values.
Returns
========================================
| The first iterator i in the range [first1,last1) such that for some iterator j in the range [first2,last2) the following conditions hold: ``*i == *j``, ``pred(*i,*j)``.
| Returns last1 if [first2,last2) is empty or if no such iterator is found.
Examples
========================================
.. sourcecode:: c++
#include <sprout/algorithm/find_first_of.hpp>
#include <sprout/array.hpp>
#include <sprout/container.hpp>
using namespace sprout;
SPROUT_STATIC_CONSTEXPR auto input1 = array<int, 10>{{1, 2, 3, 4, 5, 1, 2, 3, 4, 5}};
SPROUT_STATIC_CONSTEXPR auto input2 = array<int, 3>{{3, 4, 5}};
SPROUT_STATIC_CONSTEXPR auto result = sprout::find_first_of(begin(input1), end(input1), begin(input2), end(input2));
static_assert(result != end(input1), "found an element equal to an one of input2 from input1.");
static_assert(result - begin(input1) == 2, "a found position is 2.");
Complexity
========================================
| At most ``(last1 - first1) * (last2 - first2)`` applications of the corresponding predicate.
| Recursive function invocations in *O(logN)* (logarithmic) depth.
Header
========================================
| ``sprout/algorithm/find_first_of.hpp``
| Convenience header: ``sprout/algorithm.hpp``