On Monday, 5 February 2018 at 20:45:22 UTC, H. S. Teoh wrote:
On Mon, Feb 05, 2018 at 03:23:20PM -0500, Steven Schveighoffer
via Digitalmars-d wrote:
On 2/5/18 2:30 PM, H. S. Teoh wrote:
> Even better yet:
>
> byte b;
> b = -b; // Deprecation error
>
> WAT????
In the future, -b will be typed as an int, so you can't
reassign it to b. You can see this today with
-transition=intpomote:
Error: cannot implicitly convert expression -cast(int)b of
type int to
byte
[...]
Honestly, this just makes narrow int types basically useless
when it comes to any arithmetic at all.
In fact you really shouldn’t do arithmetic on narrow integers,
especially as loop counters.
It usually results in suboptimal machine code on optimizing
compilers.
That leaves arrays of bytes and array-wise operations though,
SIMD by definition can operate on a pack of e.g. byte-sized
integers.
Bottom line is to use narrow integers only as a way to pack data
and for SIMD operations in arrays.
T
