Document: P3688R6

Author: Jan Schultke, Corentin Jabot

Date: 2026-02-21

Audience: SG16 (Unicode)

Revision 6 still aims at a dedicated ascii header with constexpr, locale-independent ASCII tests and transforms across char, wchar_t, char8_t, char16_t, and char32_t—basically fixing the cctype / locale pain without pretending your encoding is Unicode-aware. If you mirror-fetch papers and your client 401s with "Missing Authentication header", that is on the endpoint, not the PDF; grab the public HTML from https://wg21.link/p3688r6 or https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2026/p3688r6.html instead.