Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.
The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.
This is a re-commit. The previous commit was reverted because it exposed
a pre-existing bug that has since been fixed / worked around; see
PR48434.
Differential Revision: https://reviews.llvm.org/D91311
GitOrigin-RevId: 2a2c228c7ada0a5d77c48b4d445ab0013ca0ae19
diff --git a/include/string_view b/include/string_view
index 7c3214f..44ffb02 100644
--- a/include/string_view
+++ b/include/string_view
@@ -192,7 +192,26 @@
_LIBCPP_BEGIN_NAMESPACE_STD
template<class _CharT, class _Traits = char_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS basic_string_view {
+ class _LIBCPP_TEMPLATE_VIS basic_string_view;
+
+typedef basic_string_view<char> string_view;
+#ifndef _LIBCPP_NO_HAS_CHAR8_T
+typedef basic_string_view<char8_t> u8string_view;
+#endif
+typedef basic_string_view<char16_t> u16string_view;
+typedef basic_string_view<char32_t> u32string_view;
+typedef basic_string_view<wchar_t> wstring_view;
+
+template<class _CharT, class _Traits>
+class
+ _LIBCPP_PREFERRED_NAME(string_view)
+#ifndef _LIBCPP_NO_HAS_CHAR8_T
+ _LIBCPP_PREFERRED_NAME(u8string_view)
+#endif
+ _LIBCPP_PREFERRED_NAME(u16string_view)
+ _LIBCPP_PREFERRED_NAME(u32string_view)
+ _LIBCPP_PREFERRED_NAME(wstring_view)
+ basic_string_view {
public:
// types
typedef _Traits traits_type;
@@ -776,14 +795,6 @@
operator<<(basic_ostream<_CharT, _Traits>& __os,
basic_string_view<_CharT, _Traits> __str);
-typedef basic_string_view<char> string_view;
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-typedef basic_string_view<char8_t> u8string_view;
-#endif
-typedef basic_string_view<char16_t> u16string_view;
-typedef basic_string_view<char32_t> u32string_view;
-typedef basic_string_view<wchar_t> wstring_view;
-
// [string.view.hash]
template<class _CharT>
struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >