rust-lang/rust — pull request #17157 by nikomatsakis (2014-09-10 23:57:24+00:00)
Title: Avoid creating cyclic types during inference

Avoid ever constructing cyclic types in the first place, rather than detecting them in resolve. This simplifies logic elsewhere in the compiler, in particular on the trait reform branch.

r? @pnkfelix or @pcwalton

cc #5527