Newbie question about Bound type

I have difficult to find out how mir::TyKind::Bound type is substituted by a concrete type. I can figure out that mir::TyKind::Param is substituted by the SubstFolder. So there might be a similar way that mir::TyKind::Bound get substituted. Any suggestion is appreciated. Thanks in advance.

According to the docs it is only used inside the trait solver. TyKind in rustc_middle::ty - Rust

thanks for narrowing the scope. I'll check it.