> Within a single crate (more specifically, codegen unit) the inlining is possible Cross-crate inlining happens all the time. In order to be eligible for inlin

> Within a single crate (more specifically, codegen unit) the inlining is possible Cross-crate inlining happens all the time. In order to be eligible for inlining, a function needs to have its IR included in the object's metadata. This happens automatically for every generic function (it's the only way monomorphization can work), and for non-generic functions can be enabled manually via the `#[inline]` attribute (which does not force inlining, it only makes it possible to inline at the backend's discretion). However, as you, say, if you have LTO enabled then "cross-crate" inlining can happen regardless, since it's all just one giant compilation unit at that point.