Template Function thrust::stable_partition(ForwardIterator, ForwardIterator, Predicate)¶
Function Documentation¶
-
template<typename
ForwardIterator
, typenamePredicate
>
ForwardIteratorthrust
::
stable_partition
(ForwardIterator first, ForwardIterator last, Predicate pred) stable_partition
is much like partition : it reorders the elements in the range[first, last)
based on the function objectpred
, such that all of the elements that satisfypred
precede all of the elements that fail to satisfy it. The postcondition is that, for some iteratormiddle
in the range[first, last)
,pred(*i)
istrue
for every iteratori
in the range[first,middle)
andfalse
for every iteratori
in the range[middle, last)
. The return value ofstable_partition
ismiddle
.stable_partition
differs from partition in thatstable_partition
is guaranteed to preserve relative order. That is, ifx
andy
are elements in[first, last)
, andstencil_x
andstencil_y
are the stencil elements in corresponding positions within[stencil, stencil + (last - first))
, andpred(stencil_x) == pred(stencil_y)
, and ifx
precedesy
, then it will still be true afterstable_partition
thatx
precedesy
.The following code snippet demonstrates how to use
stable_partition
to reorder a sequence so that even numbers precede odd numbers.- Return
An iterator referring to the first element of the second partition, that is, the sequence of the elements which do not satisfy pred.
- Parameters
first
: The first element of the sequence to reorder.last
: One position past the last element of the sequence to reorder.pred
: A function object which decides to which partition each element of the sequence[first, last)
belongs.
- Template Parameters
ForwardIterator
: is a model of Forward Iterator, andForwardIterator's
value_type
is convertible toPredicate's
argument_type
, andForwardIterator
is mutable.Predicate
: is a model of Predicate.
#include <thrust/partition.h> ... struct is_even { __host__ __device__ bool operator()(const int &x) { return (x % 2) == 0; } }; ... int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; const int N = sizeof(A)/sizeof(int); thrust::stable_partition(A, A + N, is_even()); // A is now {2, 4, 6, 8, 10, 1, 3, 5, 7, 9}
- See
- See
partition
- See
stable_partition_copy