I really can't wrap my head around these. I fought whole day trying to figure out how to do the simplest thing one can imagine: remove an element from a doubly linked list. Here's what I've tried, see if there is a recurring mistake of thought or something:

import std.stdio;
import std.algorithm;
import std.range;
import std.container;

struct Point {
    int x;
    int y;
}

void main() {
    DList!Point points;
    points.insert(Point(0,0));
    points.insert(Point(10,10));
    points.insert(Point(5,5));
    points.insert(Point(20,20));

    points.remove(takeOne(find!(p => p.x > 7)(points[])));
    // test.d(18): Error: function std.container.DList!(Point).DList.remove (Range r) is not callable using argument types (Result)

    points.linearRemove(takeOne(find!(p => p.x > 7)(points[])));
    // test.d(21): Error: template std.container.DList!(Point).DList.linearRemove cannot deduce function from argument types !()(Result), candidates are:
    // /usr/include/dmd/phobos/std/container.d(2234):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Range))
    // /usr/include/dmd/phobos/std/container.d(2240):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Range))
    // /usr/include/dmd/phobos/std/container.d(2253):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Take!Range))

    points.remove(find!(p => p.x > 7)(points[]));
    // 0

    points.remove(takeOne(filter!(p => p.x > 7)(points[])));
    // test.d(30): Error: function std.container.DList!(Point).DList.remove (Range r) is not callable using argument types (Result)

    points.remove(filter!(p => p.x > 7)(points[]));
    // test.d(33): Error: function std.container.DList!(Point).DList.remove (Range r) is not callable using argument types (FilterResult!(__lambda3, Range))

    points.linearRemove(filter!(p => p.x > 7)(points[]));
    // test.d(36): Error: template std.container.DList!(Point).DList.linearRemove cannot deduce function from argument types !()(FilterResult!(__lambda1, Range)), candidates are:
    // /usr/include/dmd/phobos/std/container.d(2234):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Range))
    // /usr/include/dmd/phobos/std/container.d(2240):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Range))
    // /usr/include/dmd/phobos/std/container.d(2253):        std.container.DList!(Point).DList.linearRemove(R)(R r) if (is(R == Take!Range))

    foreach (Point p; points) {
        if (p.x > 7) {
            //points.remove(/* Somehow get the range */);
            break;
        }
    }

    foreach (Point p; points) {
        writeln(p.x);
    }
}


Purpose is to remove one element that matches predicate, or any amount really. Now DList.remove is defined as "Range remove(Range r)" and filter is "auto filter(Range)(Range rs) if (isInputRange!(Unqual!Range))" with explanation "The call filter!(predicate)(range) returns a new range only containing elements x in range for which predicate(x) is true." So if I understand correctly, filter should return a range that I can remove from the list. Why isn't this working?