With #[inline(always)] the body of default() will be inlined into external crates but the body will still contain calls to the LZOxide::new(), ParamsOxide::new(DEFAULT_FLAGS), Box::default() and DictOxide::new(DEFAULT_FLAGS). This ends up causing a copy of the large LZOxide to end up on the stack when used with Box::default as seen in: https://github.com/rust-lang/rust/issues/101814
With #[inline(always)] the body of default() will be inlined into external crates but the body will still contain calls to the LZOxide::new(), ParamsOxide::new(DEFAULT_FLAGS), Box::default() and DictOxide::new(DEFAULT_FLAGS). This ends up causing a copy of the large LZOxide to end up on the stack when used with Box::default as seen in: https://github.com/rust-lang/rust/issues/101814