Yes, I understand that. I'm requesting feedback as to whether reinterpret_cast should be made to work between floating-point types having identical representations. Should I bother to author such a proposal or would I be wasting my time? Also, insight into the intended purpose of std::float32_t and std::float64_t would be welcome. It seems that C++ intends them to be used in scientific codes. Yes? -----Original message----- From: Jason McKesson via Std-Proposals <std-proposals_at_[hidden]> Sent: Sunday, August 24 2025, 11:37 am To: std-proposals_at_[hidden] <std-proposals_at_[hidden]> Cc: Jason McKesson <jmckesson_at_[hidden]> Subject: Re: [std-proposals] TBAA and extended floating-point types On Sun, Aug 24, 2025 at 12:31 PM Paul Caprioli via Std-Proposals <std-proposals_at_[hidden]> wrote: > > > You can reinterpret_cast char8_t* to char* just fine. > > But one cannot reinterpret_cast between std::float64_t* and double* (and use the resulting pointer). The reason that the `char*` cast works is because `char*` gets to be an exception to aliasing *in general*. It wasn't done to specifically allow this use case; it's just a happy accident. > P1467R9 discusses implicit conversions, overload resolution, and adding extended floating-point types to <cmath>. > It seems the extended floating-point types were intended to be used. -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals