Digest for comp.lang.c++@googlegroups.com - 4 updates in 1 topic

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Bonita Montero <Bonita.Montero@gmail.com>: Dec 29 08:00PM +0100 I just wanted to give a set a load-factor of +Inf. So I just wrote 1.0f / 0.0f to prevent numeric_limits<float>::infinity() because the first is shorter. MSVC took this as an error but clang++ and clang-cl accepted the code. Which compiler is right ?

Jack Lemmon <invalid@invalid.net>: Dec 29 07:15PM On 29/12/2021 19:00, Bonita Montero wrote: > 1.0f / 0.0f to prevent numeric_limits<float>::infinity() because > the first is shorter. MSVC took this as an error but clang++ and > clang-cl accepted the code. Which compiler is right ?   In mathematics, a number divided by zero is undefined. So I would say MSVC is correct though it should have simply said <Nan>.

Bonita Montero <Bonita.Montero@gmail.com>: Dec 29 09:20PM +0100 Am 29.12.2021 um 20:15 schrieb Jack Lemmon: >> clang-cl accepted the code. Which compiler is right ?   > In mathematics, a number divided by zero is undefined. > So I would say MSVC is correct though it should have simply said <Nan>.   No, it's infinity. 0.0 / 0.0 is NaN.

"james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu>: Dec 29 01:08PM -0800 On Wednesday, December 29, 2021 at 2:00:21 PM UTC-5, Bonita Montero wrote: > 1.0f / 0.0f to prevent numeric_limits<float>::infinity() because > the first is shorter. MSVC took this as an error but clang++ and > clang-cl accepted the code. Which compiler is right ?   Both are right. "If the second operand of / or % is zero the behavior is undefined." (7.6.5p4). When the behavior is undefined, there's no wrong way to handle it. In particular, it's permitted to implement ISO/IEC 60559 (== IEEE 754) semantics. I won't be able to check my copy of that standard until Monday, but off the top of my head, I think it specifies that division by 0 results in an infinity with the same sign as the numerator.

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