Should this work?

[John Colvin]

On Thursday, 9 January 2014 at 14:08:02 UTC, Manu wrote:
> This works fine:
>   string x = find("Hello", 'H');
>
> This doesn't:
>   string y = find(retro("Hello"), 'H');
>   > Error: cannot implicitly convert expression 
> (find(retro("Hello"), 'H'))
> of type Result!() to string

In order to return the result as a string it would require an 
allocation. You have to request that allocation (and associated 
eager evaluation) explicitly

string y = "Hello".retro.find('H').to!string;


However, I think to get the expected result from unicode you need

string y = "Hello".byGrapheme.retro.find('H').to!string;

but I might be wrong.