thrust

◆ upper_bound() [6/8]

template<class ForwardIterator , class InputIterator , class OutputIterator >
OutputIterator thrust::upper_bound ( ForwardIterator  first,
ForwardIterator  last,
InputIterator  values_first,
InputIterator  values_last,
OutputIterator  result 
)

upper_bound is a vectorized version of binary search: for each iterator v in [values_first, values_last) it attempts to find the value *v in an ordered range [first, last). Specifically, it returns the index of last position where value could be inserted without violating the ordering.

Parameters
firstThe beginning of the ordered sequence.
lastThe end of the ordered sequence.
values_firstThe beginning of the search values sequence.
values_lastThe end of the search values sequence.
resultThe beginning of the output sequence.
Template Parameters
ForwardIteratoris a model of Forward Iterator.
InputIteratoris a model of Input Iterator. and InputIterator's value_type is LessThanComparable.
OutputIteratoris a model of Output Iterator. and ForwardIterator's difference_type is convertible to OutputIterator's value_type.
Precondition
The ranges [first,last) and [result, result + (last - first)) shall not overlap.

The following code snippet demonstrates how to use upper_bound to search for multiple values in a ordered range.

...
thrust::device_vector<int> input(5);
input[0] = 0;
input[1] = 2;
input[2] = 5;
input[3] = 7;
input[4] = 8;
values[0] = 0;
values[1] = 1;
values[2] = 2;
values[3] = 3;
values[4] = 8;
values[5] = 9;
thrust::upper_bound(input.begin(), input.end(),
values.begin(), values.end(),
output.begin());
// output is now [1, 1, 2, 2, 5, 5]
See also
http://www.sgi.com/tech/stl/upper_bound.html
upper_bound
equal_range
binary_search