Customizing printing of structs (writeln / to!sth behavior).

[ciechowoj via Digitalmars-d-learn]

It there a way to change how writeln converts structs to strings? 
I read in the documentation it uses to!string to convert the 
struct. Is there a way to overload to!string for my own type?

Let say I have:

struct Point {
     int x, y;
}

and I want writeln(Point(3, 4)); to print "[3, 4]" instead of 
"Point(3, 4)".