`<string_view>`: suppress warning about annotation 'NullTerminated' (#3032)

Co-authored-by: Casey Carter <Casey@Carter.net>

stl/inc/xstring

@@ -1191,6 +1191,10 @@ struct pointer_traits<_String_view_iterator<_Traits>> {
 };
 #endif // _HAS_CXX20
 
+#pragma warning(push)
+// Invalid annotation: 'NullTerminated' property may only be used on buffers whose elements are of integral or pointer
+// type
+#pragma warning(disable : 6510)
 
 template <class _Elem, class _Traits>
 class basic_string_view { // wrapper for any kind of contiguous character buffer
@@ -1656,6 +1660,8 @@ private:
     size_type _Mysize;
 };
 
+#pragma warning(pop)
+
 #ifdef __cpp_lib_concepts
 template <contiguous_iterator _Iter, sized_sentinel_for<_Iter> _Sent>
 basic_string_view(_Iter, _Sent) -> basic_string_view<iter_value_t<_Iter>>;

tests/std/tests/P0220R1_string_view/test.cpp

@@ -5,6 +5,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdlib>
+#include <cstring>
 #include <deque>
 #include <limits>
 #include <sstream>
@@ -1255,6 +1256,38 @@ static_assert(!is_constructible_v<string, nullptr_t>, "constructing string from
 static_assert(!is_assignable_v<string&, nullptr_t>, "assigning nullptr_t to string is prohibited");
 #endif // _HAS_CXX23
 
+// Also test that no C6510 warning
+struct char_wrapper {
+    char c;
+};
+
+template <>
+struct std::char_traits<char_wrapper> {
+    using char_type = char_wrapper;
+
+    static bool eq(char_wrapper lhs, char_wrapper rhs) {
+        return lhs.c == rhs.c;
+    }
+
+    static size_t length(const char_wrapper* a) {
+        static_assert(sizeof(char_wrapper) == 1, "strlen requires this");
+        return strlen(reinterpret_cast<const char*>(a));
+    }
+
+    static int compare(const char_wrapper* lhs, const char_wrapper* rhs, size_t count) {
+        return char_traits<char>::compare(
+            reinterpret_cast<const char*>(lhs), reinterpret_cast<const char*>(rhs), count);
+    }
+};
+
+using WrappedSV = basic_string_view<char_wrapper, char_traits<char_wrapper>>;
+
+void test_C6510_warning() { // compile-only
+    char_wrapper a[] = {{'a'}, {'b'}, {'c'}, {'\0'}};
+    WrappedSV sv(a);
+    (void) sv;
+}
+
 int main() {
     test_case_default_constructor();
     test_case_ntcts_constructor();