An #[inline(..)]
attribute was incorrectly placed on something other than a function or method.
Example of erroneous code:
#[inline(always)] struct Foo; #[inline(never)] impl Foo { // ... }
#[inline]
hints the compiler whether or not to attempt to inline a method or function. By default, the compiler does a pretty good job of figuring this out itself, but if you feel the need for annotations, #[inline(always)]
and #[inline(never)]
can override or force the compiler's decision.
If you wish to apply this attribute to all methods in an impl, manually annotate each method; it is not possible to annotate the entire impl with an #[inline]
attribute.