Reports the use of the syntax deprecated from Ruby 1.9. For example, : instead of then for one-line if, when, unless.

Example:

condition = true
if condition: 1 else 0 # -> if condition then 1 else 0
unless condition: 0 else 1 # -> unless condition then 0 else 1

value = 1
case value
when 1: true # -> when 1 then true
end