Pitfalls of delegates inside ranges

[Joseph Rushton Wakeling]

On 02/09/13 15:39, Artur Skawina wrote:
> While this may not seem ideal, sometimes you do *not* want to do it
> (when you need to keep the original context), so there are no obvious
> alternatives that would handle all cases automagically.

I'm sure there are valid use cases where this behaviour is desirable.  In fact, 
all approaches to creating reference-type structs rest on this, although in 
those cases the reference is usually a pointer to a payload rather than a 
delegate to a function.

The point is, it's a risk if you don't appreciate how value and reference types 
intermingle -- and even when you do in principle, it's easy to accidentally 
overlook in practice.  The Phobos unittests, which for RandomSample are very 
extensive, didn't catch this problem.