[libcxx-commits] [libcxx] [libc++][hardening] Reclassify string_view(ptr, len)'s size assertion (PR #79297)

[Konstantin Varlamov via libcxx-commits]

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@@ -307,9 +307,10 @@ public:
       : __data_(__s),
         __size_(__len) {
 #if _LIBCPP_STD_VER >= 14
-    // This will result in creating an invalid `string_view` object -- some calculations involving `size` would
-    // overflow, making it effectively truncated.
-    _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(
+    // Allocations must fit in `ptrdiff_t` for pointer arithmetic to work. If `__len` exceeds it, the input
+    // range could not have been valid. Most likely the caller underflowed some arithmetic and inadvertently
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var-const wrote:

I think the maximum size of an object is implementation-defined but on Clang it's considerably smaller than the maximum value of `ptrdiff_t` (further strengthening the argument that the input range couldn't have been valid).

https://github.com/llvm/llvm-project/pull/79297