Re: Is using function() in templates possible at all?

[Alex via Digitalmars-d-learn]

On Wednesday, 11 April 2018 at 21:07:03 UTC, Sjoerd Nijboer wrote:

class SortedList(T, int function(T) comparer)

I would say, alias template parameter is your friend.
https://dlang.org/spec/template.html#TemplateAliasParameter

´´´
import std.stdio;
import std.range;

void main()
{
        auto list = new SortedList!(Vector3, v => v.y)();

        assert(list.array.empty);
        list.foo(Vector3.init);
}

struct Vector3 { float x, y, z; }

class SortedList(T, alias comparer)
{
        T[] array;
        
        auto foo(T t)
        {
                for(int i = 0; i < array.length; i++)
                {
                        if(comparer(this.array[i]) <=  comparer(t))
                        {
                                //do stuff
                                array[i] = t;
                        }
                }
        }
}
´´´