How about a function called contains() for the module std.array?

[Les De Ridder]

On Saturday, 19 October 2019 at 21:47:57 UTC, Murilo wrote:
> I needed a function that tells if an array contains the 
> elements of another, as in `[1, 2, 3, 4, 5, 6].contains([6, 
> 4])` by returning a `bool`. I did not find such function so I 
> made my own version but I'm unable to submit a PR on GitHub 
> since I don't know how to write a function using that style 
> that I saw on GitHub. I imagine that maybe you guys could take 
> my function and refactor it so it will be according to your 
> rules and then add it to std.array. What do you think?
> Here is my function:
> //This function returns a bool telling if an array totally 
> contains the elements of a smaller array
> import std.algorithm.searching : countUntil;
> import std.algorithm.sorting : sort;
>
> bool contains(long[] a, long[] b)
> {
>     //first we sort both of them
>     sort(a);
>     sort(b);
>     //now we check them using slices and return the result
>     return b == a[a.countUntil(b[0]) .. a.countUntil(b[$ - 1]) 
> + 1];
> }
> /*
> Example:
> long[] a = [3, 9, 1, 4, 7, 6, 5, 8, 2];
> long[] b = [5, 4, 6];
> writeln(contains(a, b));
> */

You could do something like this:

     import std.stdio;
     import std.algorithm : all, canFind;

     auto a = [1, 2, 3, 4, 5, 6];
     auto f = [3, 5, 6].all!(n => a.canFind(n));
     writeln(f);

PS: this should probably have been posted to the Learn list.