Re: Mathematical rounding

[via Digitalmars-d]

On Thursday, 16 October 2014 at 05:24:23 UTC, Andrei Alexandrescu 
wrote:
On 10/15/14, 8:11 PM, Elena wrote:
Hi,every one!
How can I realize mathematical rounding (not banking) for 
Double in D
0.4 -> 0
0.5 -> 1
1.5 -> 2
2.5 -> 3
3.5 -> 4  ?
Thank you.

Add 0.5 and then cast to integral. -- Andrei

This would be the "round half up" mode that produce 0 for -0.5:

floor(x+0.5)

Whereas "round nearest" should produce -1 for -0.5:

floor(abs(x)+0.5)*sgn(x)