rustc: T: 'empty always holds for all types. #42482
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nikomatsakis approved these changes Jun 6, 2017
bors added a commit that referenced this pull request Jun 7, 2017
rustc: T: 'empty always holds for all types. Fixes #42467 by special-casing `ReEmpty` to always hold, even for parameters. The reason this is the case is that `ReEmpty` is the result of inferring a region variable with no constraints attached to it, so there is no lifetime a type would contain which would be strictly shorter. r? @nikomatsakis
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Fixes #42467 by special-casing
ReEmptyto always hold, even for parameters.The reason this is the case is that
ReEmptyis the result of inferring a region variable with no constraints attached to it, so there is no lifetime a type would contain which would be strictly shorter.r? @nikomatsakis