std::set_difference

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Defined in header <algorithm>

template< class InputIterator1, class InputIterator2, class OutputIterator >

OutputIterator set_difference( InputIterator1 first1, InputIterator1 last1,
               InputIterator2 first2, InputIterator2 last2,

               OutputIterator d_first );
(1)
template< class InputIterator1, class InputIterator2,

          class OutputIterator, class Compare >
OutputIterator set_difference( InputIterator1 first1, InputIterator1 last1,
               InputIterator2 first2, InputIterator2 last2,

               OutputIterator d_first, Compare comp );
(2)

Copies the elements from the sorted range [first1, last1) which are not found in the sorted range [first2, last2) to the range beginning at d_first. The resulting range is also sorted. The first version expects both input ranges to be sorted with operator<, the second version expects them to be sorted with the given comparison function comp. Equivalent elements are treated individually, that is, if some element is found m times in [first1, last1) and n times in [first2, last2), it will be copied to d_first exactly std::min(m-n, 0) times. The resulting range cannot overlap with either of the input ranges.

Contents

[edit] Parameters

first1, last1 - the range of elements to examine
first2, last2 - the range of elements to search for
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 InputIterator can be dereferenced and then implicitly converted to both of them. ​

[edit] Return value

Iterator past the end of the constructed range.

[edit] Complexity

At most 2·(N1+N2-1) comparisons, where N1 = std::distance(first1, last1) and N2 = std::distance(first2, last2).

[edit] Equivalent function

[edit] Example

[edit] See also

includes
returns true if one set is a subset of another
(function template)
set_symmetric_difference
computes the symmetric difference between two sets
(function template)