confused with data types

[arturg]

On Sunday, 18 February 2018 at 13:08:09 UTC, thorstein wrote:
> On Sunday, 18 February 2018 at 12:51:04 UTC, thorstein wrote:
>> // Solution 1
>> foreach(row; arr)
>> { foreach(col; row)
>>   { col[] *= skalar;
>>   }
>> }
>> return arr;
>>
>> // Solution 2
>> import std.array;
>> return array(arr.map!(b => array(b[].map!(c => 
>> array(c[].map!(d => d * skalar))))));
>>
>> // Solution 3
>> import std.algorithm;
>> arr.each!(a => a[].each!(b => b[] *= skalar));
>> return arr;
>>
>> Q#1:
>> Does the compiler optimizes all solutions equally strong or 
>> does it prefer implementations like solution 1?
>>
>> Q#2:
>> Solution 2 is a 1-liner but a bit harder to read. Why reducing 
>> solution 3 to:
>> return arr.each!(a => a[].each!(b => b[] *= skalar));
>> gives a compile error? I do writeln() the function result.
>>
>> Q#3:
>> If I can:
>> static import std.array;
>> return std.array.array(arr.map!(b => 
>> std.array.array(b[].map!(c =>...
>>
>> How would I apply a similar version with 'static import 
>> std.algorithm' to solution 3?
>> static import std.algorithm;
>> std.algorithm.arr.each!(a => a[]... //does obviously not work
>>
>> Thanks, thorstein
>
> Sorry, Solution 2 should be:
>
> import std.array;
> return array(arr.map!(b => array(b[].map!(c => c[] *= 
> skalar))));
>
> and is as readable as Solution 3. However, Q#2 still remains.

Q#1: i would guess solution 1 would be the fastest and solution 2 
the slowest.
Q#2: you get a error because each returns void.
Q#3: you cant use ufcs with static imports, you have to call the 
function normaly:
     static import algo = std.algorithm;
     algo.each!((a) => algo.each!((b) => b[] *= skalar)(a))(arr);