join of range of ranges?

[Peter Alexander]

On Sunday, 22 September 2013 at 14:26:14 UTC, bearophile wrote:
>     auto r2 = [1, 2]
>               .map!(x => [1, 2].map!(y => '*'))
>               .join("_");

The problem is that you are trying to map a range of range of 
chars with a range of dchars.

auto r2 = [1, 2]
               .map!(x => [1, 2].map!(y => cast(dchar)'*'))
               .join("_");

This works.

I really wish character literals in D where always dchar.