Reading unicode string with readf ("%s")

[Ivan Kazmenko via Digitalmars-d-learn]

On Monday, 3 November 2014 at 19:37:20 UTC, Ivan Kazmenko wrote:
> 	readf ("%s", &s);

Worth noting: this reads to end-of-file (not end-of-line or 
whitespace), and reading the whole file into a string was what I 
indeed expected it to do.

So, if there is an idiomatic way to read the whole file into a 
string which is Unicode-compatible, it would be great to learn 
that, too.