One thing I often find myself in need of is the ability to get back at the source range of a range iteration.

Here's a few examples:

// Read a file up until a line containing "END"
string beforeEND = readText(filename).splitter('\n').findBefore(["END"])[0].source;

// Find the largest group of characters
string aaac = "bbaaac".group().minPos!("a[1] > b[1]").source;

// Find first number that has different sign from preceding numbers
int three = [-1, -2, 3].map!(sgn).uniq().drop(1).source.source.front;


As far as I'm aware, there's no easy way to do any of the above without source.

There's also examples where alternatives are possible, but having the source range available enables an alternate approach.

// Find the number whose square is 25 (could be done using predicated find)
int five = iota(10).map!("a*a").find(25).source.front;


Has anyone else ever needed something like this? Is it worth adding to Phobos?