double vs real

[Diggory]

On Thursday, 30 May 2013 at 16:18:44 UTC, Shriramana Sharma wrote:
> Hello. I like that D exposes to me the real type to maximally 
> utilize
> the machine's numerical precision. Since I am writing a program
> (currently in C++ but I am thinking of moving to D) that has to 
> handle
> lots of fractional numbers (calculating offset curves and such) 
> I am
> wondering whether/when I should real instead of double or even 
> any
> arguments in favour of staying with double (compatibility with
> C/C++?). Any pointers appreciated please? I checked the FAQ but 
> it
> doesn't seem to mention this.
>
> Thanks!

Since D does all operations at highest possible precision anyway 
(even for double or float) it only makes a difference when the 
value is being stored to memory and then read back again.

I would recommend aliasing double or real to a custom name and 
then using that. Then when you're done you can easily switch 
between them and see how it affects precision in your particular 
case and decide what's best.