std::merge

From Cppreference

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Defined in header <algorithm>
​template< class InputIterator1, class InputIterator2, class OutputIterator > OutputIterator merge( InputIterator1 first1, InputIterator1 last1,                       InputIterator2 first2, InputIterator2 last2                       OutputIterator d_first );​	(1)
​template< class InputIterator1, class InputIterator2, class OutputIterator, class Compare> OutputIterator merge( InputIterator1 first1, InputIterator1 last1,                       InputIterator2 first2, InputIterator2 last2                       OutputIterator d_first, Compare comp );​	(2)

Merges two sorted ranges [first1, last1) and [first2, last2) into one sorted range beginning at d_first. The first version uses ​operator<​ to compare the elements, the second version uses the given comparison function comp.

Contents 1 Parameters 2 Return value 3 Complexity 4 Example 5 See also

Parameters

first1, last1	-	the first range of elements to merge
first2, last2	-	the second range of elements to merge
d_first	-	the beginning of the destination range
comp	-	comparison function which returns ​​true​ if the first argument is less than the second. The signature of the comparison function should be equivalent to the following: ​bool cmp(const Type1 &a, const Type2 &b);​ The signature does not need to have ​const &​, but the function must not modify the objects passed to it. The types ​Type1​ and ​Type2​ must be such that an object of type ​RandomAccessIterator​ can be dereferenced and then implicitly converted to both of them. ​

Return value

an output iterator to element past the last element copied.

Complexity

At most ​std::distance(first1, last1) + std::distance(first2, last2) + 1​ comparisons.

Example

This section is incomplete

See also

partial_sort	sorts the first N elements of a range (function template)
sort	sorts a range into ascending order (function template)
stable_sort	sorts a range of elements while preserving order between equal elements (function template)