Fixed-layout floating-point type aliases

Published Proposal,

This version:
ISO/IEC JTC1/SC22/WG21 14882: Programming Language — C++

1. Why this paper is empty

This paper has been merged into P1467, starting with P1467R4. P1467 (extended floating-point types) and P1468 (standard names for well-known layouts) were separate proposals when first written. But over time they have become intertwined, with design decisions in one paper affecting the feasibility of the other. So the two papers have now been merged into a single proposal. This version of P1468 exists merely to point people to where the contents now live.

2. Revision history

2.1. R0 -> R1 (pre-Cologne)

  1. Add the requirement that the types must not alias any of the standard floating-point types.

  2. Add a design question about feature-test macros.

  3. Add a section on QoI - should we strongly encourage that the aliases to have a hardware implementation?

2.2. R1 -> R2 (pre-Belfast)

Changes based on feedback in Cologne from SG6, LEWGI, and EWGI. Further changes came from further development of the paper by the authors.

2.3. R2 -> R3 (pre-Prague)

Changes based on feedback in Belfast from EWG.

2.4. R3 -> R4 (Summer 2020)

Merge the contents into P1467R4, leaving an empty shell of a paper.