https://doc.rust-lang.org/stable/nightly-rustc/rustc_middle/ty/context/tls/struct.ImplicitCtxt.html
ImplicitCtxt in rustc_middle::ty::context::tls - Rust
This is the implicit state of rustc. It contains the current `TyCtxt` and query. It is updated when creating a local interner or executing a new query....
rustcmiddletycontexttls