How to walk over two arrays by ref in beautyfull way?

[vitalfadeev]

On Monday, 10 June 2019 at 07:45:42 UTC, vitalfadeev wrote:
> On Monday, 10 June 2019 at 07:41:40 UTC, vitalfadeev wrote:
>> How to?
>>
>> I plan scan First array with checkers:
>> [checker, checker, checker]
>>
>> ...and store result to Second array:
>> [0, 0, 1]
>>
>> In next code 'r' not reference. But expected ref.
>>
>>     import std.range : zip;
>>
>>     foreach(checker, ref r; zip(checkers, result.set)) {
>>        r = checker();
>>     }
>>
>> What is the best way for speed and beautyfull D code?
> Detailed:

import std.range : zip;
import std.stdio : writeln, write;


struct Result {
     byte[] set;
}

alias Callback = bool function();


Callback[] checkers;
Result result;


bool false_cb() { return 0; }
bool true_cb() { return 1; }


void init() {
	checkers ~= &false_cb;
	checkers ~= &false_cb;
	checkers ~= &true_cb;

	result.set.length = checkers.length;
}


void check() {
     foreach(checker, ref r; zip(checkers, result.set)) {
         r = checker();
     }
}


void print() {
     foreach(r; result.set) {
         write(r, " ");
     }
     writeln();
}


void main() {
     init();
     check();
     print();
}



https://run.dlang.io/is/Plqcq5