When pattern matching on GADTs, abstract (phantom) types are not considered structurally different from concrete ones #7360
Description
Original bug ID: 7360
Reporter: rlepigre
Status: resolved (set by @damiendoligez on 2016-09-28T12:18:15Z)
Resolution: won't fix
Priority: normal
Severity: minor
Version: 4.03.0
Category: typing
Duplicate of: #7028
Related to: #5985
Monitored by: @gasche @yallop
Bug description
A GADT which uses abstract types (or phantom types defined in another module) leads to problems with pattern matching exhaustiveness checking. See the examples.
Steps to reproduce
Just call "ocaml" on the example files.