void value expressions make no sense

void_value_expressions.rb

-> { a = case when true then return end } # this is allowed
-> { a = if true then return end }        # this is not
-> { a = if true then return; 2 end }     # this is

-> { a = (true && return) } # this is allowed
-> { a = (return && true) } # this is not

-> { a = begin;  return
         rescue; return
         ensure; return
         end }                # this is allowed
-> { a = begin; return; end } # this is not

Ruby is insane, because is genial!