Fix implicit closure return type generation for libsyntax#49279

Merged

bors merged 2 commits intorust-lang:masterfrom

varkor:generated-closure-return-type

Mar 27, 2018

Commits on Mar 22, 2018

Use FunctionRetTy::Default rather than an explicit TyKind::Infer for lambda-building
varkor
committed
Optimise decode return expression for unit structs
varkor
committed