Nordlöw:
What do you mean by sufficient value?
Every thing you add to Phobos std.algorithm&std.range increases the amount of things D programmers have to understand and keep in _active memory_. So you have to balance the desire to add specialized functionality with the desire to keep that complexity low. And I think adding sortBy isn't a good idea.
If you really want to do something like that, I think it's better to add something more like Python "operator.attrgetter" (https://docs.python.org/2/library/operator.html ), that can be used with the standard sort:
items.sort!(fieldGetter("field1", "field2")); Bye, bearophile