diff --git a/src/stability.md b/src/stability.md index bf82d8517..ac77ad3f1 100644 --- a/src/stability.md +++ b/src/stability.md @@ -49,11 +49,11 @@ marks an item as stabilized. Note that stable functions may use unstable things ## rustc_const_unstable -The `#[rustc_const_unstable(feature = "foo", issue = "1234", reason = "lorem ipsum")]` -has the same interface as the `unstable` attribute. It is used to mark -`const fn` as having their constness be unstable. This allows you to make a -function stable without stabilizing its constness or even just marking an existing -stable function as `const fn` without instantly stabilizing the `const fn`ness. +The `#[rustc_const_unstable(feature = "foo", issue = "1234", reason = "lorem +ipsum")]` has the same interface as the `unstable` attribute. It is used to mark +`const fn` as having their constness be unstable. Every `const fn` with +stability attributes should carry either this attribute or +`#[rustc_const_stable]` (see below). Furthermore this attribute is needed to mark an intrinsic as `const fn`, because there's no way to add `const` to functions in `extern` blocks for now.