purity question

[Ola Fosheim Grøstad via Digitalmars-d-learn]

On Monday, 29 May 2017 at 11:25:06 UTC, ketmar wrote:
> almost all of them, 'cause they depends on FPU rounding 
> settings.

Well, yeah. IIRC contemporary floating point machine language 
instructions allow embedding of rounding mode into the 
instruction.

A pity languages are lagging behind, stuck in the 1980s...

WebAssembly is locking it to the default IEEE754-2008 
round-to-even. Which is reasonable as they aim for max 
portability, albeit a bit limiting.