char array weirdness

[ag0aep6g via Digitalmars-d-learn]

On 31.03.2016 07:40, Jack Stouffer wrote:
> $ ldc2 -O3 -release -boundscheck=off test.d
> $ ./test
> auto-decoding        1 sec, 757 ms, and 946 μs
> byCodeUnit        87 ms, 731 μs, and 8 hnsecs
> byGrapheme        14 secs, 769 ms, 796 μs, and 6 hnsecs

So the auto-decoding version takes about twenty times as long as the 
non-decoding one (1758 / 88 ≅ 20).

I still think the allocations from the `.array` calls should be 
eliminated to see how just iterating compares.

Here's a quick edit to get rid of the `.array`s:
----
uint accumulator = 0;
void test(char[] var)
{
     foreach (dchar d; var) accumulator += d;
}
void test2(char[] var)
{
     foreach (c; var.byCodeUnit) accumulator += c;
}
----

I get theses timings then:
----
auto-decoding           642 ms, 969 μs, and 1 hnsec
byCodeUnit              84 ms, 980 μs, and 3 hnsecs
----
And 643 / 85 ≅ 8.