Fix zip_iterator::distance_to to work with non-RA iters.

alliepiper · alliepiper · commit 03df551a4ac2 · 2025-11-25T16:40:34.000Z
diff --git a/thrust/thrust/iterator/zip_iterator.h b/thrust/thrust/iterator/zip_iterator.h
@@ -46,6 +46,7 @@
 #include <thrust/type_traits/integer_sequence.h>
 
 #include <cuda/std/__iterator/advance.h>
+#include <cuda/std/__iterator/distance.h>
 #include <cuda/std/__type_traits/conditional.h>
 #include <cuda/std/__type_traits/enable_if.h>
 #include <cuda/std/__type_traits/is_constructible.h>
@@ -302,7 +303,7 @@ class _CCCL_DECLSPEC_EMPTY_BASES zip_iterator : public detail::make_zip_iterator
   inline _CCCL_HOST_DEVICE typename super_t::difference_type
   distance_to(const zip_iterator<OtherIteratorTuple>& other) const
   {
-    return get<0>(other.get_iterator_tuple()) - get<0>(get_iterator_tuple());
+    return ::cuda::std::distance(get<0>(get_iterator_tuple()), get<0>(other.get_iterator_tuple()));
   }
 
   // The iterator tuple.

Original file line number	Diff line number	Diff line change
`@@ -46,6 +46,7 @@`
`46`	`46`	`#include <thrust/type_traits/integer_sequence.h>`
`47`	`47`
`48`	`48`	`#include <cuda/std/__iterator/advance.h>`
	`49`	`+#include <cuda/std/__iterator/distance.h>`
`49`	`50`	`#include <cuda/std/__type_traits/conditional.h>`
`50`	`51`	`#include <cuda/std/__type_traits/enable_if.h>`
`51`	`52`	`#include <cuda/std/__type_traits/is_constructible.h>`
`@@ -302,7 +303,7 @@ class _CCCL_DECLSPEC_EMPTY_BASES zip_iterator : public detail::make_zip_iterator`
`302`	`303`	`inline _CCCL_HOST_DEVICE typename super_t::difference_type`
`303`	`304`	`distance_to(const zip_iterator<OtherIteratorTuple>& other) const`
`304`	`305`	`{`
`305`		`- return get<0>(other.get_iterator_tuple()) - get<0>(get_iterator_tuple());`
	`306`	`+ return ::cuda::std::distance(get<0>(get_iterator_tuple()), get<0>(other.get_iterator_tuple()));`
`306`	`307`	`}`
`307`	`308`
`308`	`309`	`// The iterator tuple.`