[libc++] [LIBCXX-DEBUG-FIXME] <span>, like <string_view>, has no use for debug iterators.
A span has no idea what container (if any) "owns" its iterators, nor
under what circumstances they might become invalidated.
However, continue to use `__wrap_iter<T*>` instead of raw `T*` outside
of debug mode, because we've been shipping `std::span` since Clang 7
and ldionne doesn't want to break ABI. (Namely, the mangling of functions
taking `span::iterator` as a parameter.) Permit using raw `T*` there,
but only under an ABI macro: `_LIBCPP_ABI_SPAN_POINTER_ITERATORS`.
Differential Revision: https://reviews.llvm.org/D101003
NOKEYCHECK=True
GitOrigin-RevId: 6946f0ecca64f3af6b9e28cced9c982de2748f19
diff --git a/include/__config b/include/__config
index 96860c0..97d3289 100644
--- a/include/__config
+++ b/include/__config
@@ -106,6 +106,8 @@
# define _LIBCPP_ABI_OPTIMIZED_FUNCTION
// All the regex constants must be distinct and nonzero.
# define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO
+// Use raw pointers, not wrapped ones, for std::span's iterator type.
+# define _LIBCPP_ABI_SPAN_POINTER_ITERATORS
// Re-worked external template instantiations for std::string with a focus on
// performance and fast-path inlining.
# define _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
diff --git a/include/span b/include/span
index b475740..4c621ab 100644
--- a/include/span
+++ b/include/span
@@ -200,7 +200,11 @@
using const_pointer = const _Tp *;
using reference = _Tp &;
using const_reference = const _Tp &;
- using iterator = __wrap_iter<pointer>;
+#if (_LIBCPP_DEBUG_LEVEL == 2) || defined(_LIBCPP_ABI_SPAN_POINTER_ITERATORS)
+ using iterator = pointer;
+#else
+ using iterator = __wrap_iter<pointer>;
+#endif
using reverse_iterator = _VSTD::reverse_iterator<iterator>;
static constexpr size_type extent = _Extent;
@@ -375,7 +379,11 @@
using const_pointer = const _Tp *;
using reference = _Tp &;
using const_reference = const _Tp &;
- using iterator = __wrap_iter<pointer>;
+#if (_LIBCPP_DEBUG_LEVEL == 2) || defined(_LIBCPP_ABI_SPAN_POINTER_ITERATORS)
+ using iterator = pointer;
+#else
+ using iterator = __wrap_iter<pointer>;
+#endif
using reverse_iterator = _VSTD::reverse_iterator<iterator>;
static constexpr size_type extent = dynamic_extent;