Optimizing calls to methods on extensions that are inside a Swift Package

[Peter-Schorn]

You should also try @inline(__always). Make you you understand the difference between @inline(__always) and @inlineable. See

When should both @inlinable and @inline(__always) be used?

@inlinable is really about visibility--it makes the function body part of the the Swift interface for the module, rather than in internal detail. Quoting the introduction of SE-0193: The @inlinable attribute exports the body of a function as part of a module's interface, making it available to the optimizer when referenced from other modules. @inline(__always) is a compiler directive that does not change function visibility at all; it simply tells the compiler to ignore inlining heuristics…