as

1 // your own representation may be a struct
2 struct MyVector(T) { T x, y; }
3 
4 assert(PixelCoord(5, 10).as!(MyVector!double) == MyVector!double(5, 10));
5 assert(PixelCoord(5.5, 10.2).as!(MyVector!int) == MyVector!int(5, 10));
6 
7 // or it may be a tuple
8 alias MyPoint(T) = Tuple!(T, "x", T, "y");
9 
10 assert(PixelCoord(5, 10).as!(MyPoint!double) == MyPoint!double(5, 10));
11 assert(PixelCoord(5.5, 10.2).as!(MyPoint!int) == MyPoint!int(5, 10));
12 
13 // std.conv.to is used internally, so it should detect overflow
14 import std.conv : ConvOverflowException;
15 import std.exception : assertThrown;
16 assertThrown!ConvOverflowException(PixelCoord(-1, -1).as!(MyVector!ulong));