It turns out it's quite hard to have @safe pure nothrow functions. Oh, and const.

[Kagamin via Digitalmars-d]

On Sunday, 14 September 2014 at 01:38:33 UTC, Jakob Ovrum wrote:
> This is necessary for `inout` to work with callback functions, 
> such as with internal iteration (i.e. `opApply`).

Can you write a pass and xfail test for it? This scenario looks 
non-trivial.

> It can be worked around exactly the same way you would work 
> around it with functions that return a value - by duplicating 
> the function. It is essentially the same problem and thus 
> `inout` could easily be used to fix it.

Can you elaborate? I don't quite understand, what you mean.