WG21 PAPERS

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	Paper	Title	Authors	Audience
	P3104R6	Bit permutations	J. Schultke	LWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LWG Revisions R5 Tracking issue View on GitHub Disposition Date 2026-06 Abstract The C++ bit manipulation library in `<bit>` is an invaluable abstraction from hardware operations. Functions like `countl_zero` help the programmer avoid use of intrinsic functions or inline assembly.
	P3642R6	Carry-less product: std::clmul	J. Schultke	LEWG LWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LEWG LWG Revisions R5 R4 Tracking issue View on GitHub Abstract [Carry-less multiplication](https://en.wikipedia.org/wiki/Carry-less_product) is a simple numerical operation on unsigned integers. It can be a seen as a regular multiplication where `xor` is being used as a reduction instead of `+`.
	P3772R2	std::simd overloads for bit permutations	J. Schultke	LWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LWG Tracking issue View on GitHub Disposition Date 2026-06 Abstract [[P3104R4]](https://wg21%2elink/p3104r4) has been been design-approved by LEWG for C++29. During the discussion of the paper, it was not mentioned that [[P2933R4]](https://wg21%2elink/p2933r4) adds `std::simd` overloads for almost all functions in the `<bit>` header.
	P3793R2	Better shifting	B. Bi, J. Schultke	LWG SG6
Mailing Date 2026-07 Post-Brno Author(s) Brian Bi, Jan Schultke Target Audience LWG SG6 Tracking issue View on GitHub Disposition Date 2026-06 Abstract C++ has built-in shift operators, `<<` and `>>`, inherited from C with semantics essentially unchanged, including the following two inconvenient properties:
	P3899R3	Clarify the behavior of floating-point overflow	J. Schultke, M. Kretz	CWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke, Matthias Kretz Target Audience CWG Revisions R2 R1 Tracking issue View on GitHub Disposition Date 2026-06 Abstract The current specification of floating-point overflow is unclear. Floating-point overflow occurs when finite operands are used as operands, and the result cannot be represented as a finite value. For [[ISO/IEC 60559:2020]](https://www%2eiso%2eorg/standard/80985%2ehtml) floating-point numbers, this results in infinity.
	P3935R2	Rebasing <cmath> on C23	J. Schultke	LEWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LEWG Revisions R1 Tracking issue View on GitHub Abstract [[P3348R4]](https://wg21%2elink/p3348r4) rebased the C++26 standard on C23; it previously referred to C17. However, this process was deliberately left incomplete: some of the new C23 `<math.h>` features are only used by decimal floating-point types, or they require core language changes, etc.
	P3969R2	Fixing std::bit_cast of types with padding bits	J. Schultke	LEWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LEWG Revisions R1 R0 Tracking issue View on GitHub Abstract > The following use of `std::bit_cast` has undefined behavior at compile time: > > ```cpp > constexpr auto x = std::bit_cast<__int128>(0.0L); // GCC accepts (x = 0), Clang rejects > ``` > > That is because an 80-bit x87 `long double` has 6 bytes of padding, and it is undefined behavior to map those padding bits onto non-padding bits in the destination type via `std::bit_cast`. [[bit.cast]](https:/
	P4040R1	Case ranges	J. Schultke	SG22
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience SG22 Revisions R0 Tracking issue View on GitHub Abstract In 2024, [[N3370]](https://www%2eopen-std%2eorg/jtc1/sc22/wg14/www/docs/n3370%2ehtm) added support for `case` ranges to C2y. For example, the following two `switch` statements are equivalent:
	P4157R1	LEWG Slides for P3666R4	J. Schultke	EWG LEWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience EWG LEWG Revisions R0 Tracking issue View on GitHub Abstract C23 now has `_BitInt` type for N-bit integers (WG14 N2763, N2775):
	P4279R0	No Endian Views	J. Schultke	LEWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LEWG Tracking issue View on GitHub Abstract The design direction of [[P4030R1]](https://isocpp%2eorg/files/papers/P4030R1%2ehtml) Endian Views should not be pursued.
	P4305R0	Design problems with P2964R5 (User-defined element types in std::simd)	J. Schultke	LEWG
Mailing Date 2026-07 Post-Brno Author(s) Jan Schultke Target Audience LEWG Tracking issue View on GitHub Abstract This paper discusses some design problems in [[P2964R5]](https://isocpp%2eorg/files/papers/P2964R5%2ehtml).

Showing 11 of 11 papers · source: open-std.org

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