On Friday, 14 February 2014 at 11:58:43 UTC, John Colvin wrote: >> auto twice = (int a) => 2*a; >> twice(2); >> >> What's wrong with that? > > Drop the semicolon after twice(2) Yeah, with a semicolon it's a statement, so it doesn't have any result value to print. Without the semicolon it's an expression.