[GHC] #15687: Type synonym unused binds no warning?

[GHC]

#15687: Type synonym unused binds no warning?
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        Reporter:  AntC              |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.6.1
  (Parser)                           |
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:
 Type of failure:  GHC accepts       |  Unknown/Multiple
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 You could argue that you should get a warning about "unused `a`" in
 `Silly`'s definition.  But we don't warn about
 {{{
 const x y = x
 }}}
 so you might consider it inconsistent to warn about the same thing at the
 type level.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15687#comment:2>
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