[libcxx][iterator][ranges] adds `forward_iterator` and `forward_range`
Implements parts of:
* P0896R4 The One Ranges Proposal`
Depends on D100271.
Differential Revision: https://reviews.llvm.org/D100275
NOKEYCHECK=True
GitOrigin-RevId: fa3e26266cd499856c573b68bee97fefc07f24ad
diff --git a/include/iterator b/include/iterator
index d759eae..78f67dd 100644
--- a/include/iterator
+++ b/include/iterator
@@ -79,6 +79,10 @@
template<class I>
concept input_iterator = see below; // since C++20
+// [iterator.concept.forward], concept forward_iterator
+template<class I>
+ concept forward_iterator = see below; // since C++20
+
template<class Category, class T, class Distance = ptrdiff_t,
class Pointer = T*, class Reference = T&>
struct iterator