diff options
| -rw-r--r-- | src/doc/book/unsized-types.md | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/src/doc/book/unsized-types.md b/src/doc/book/unsized-types.md index 73b90355e4f..d94409a7b82 100644 --- a/src/doc/book/unsized-types.md +++ b/src/doc/book/unsized-types.md @@ -47,7 +47,7 @@ pointers, can use this `impl`. # ?Sized If you want to write a function that accepts a dynamically sized type, you -can use the special bound, `?Sized`: +can use the special syntax, `?Sized`: ```rust struct Foo<T: ?Sized> { @@ -55,6 +55,5 @@ struct Foo<T: ?Sized> { } ``` -This `?`, read as “T may be `Sized`”, means that this bound is special: it -lets us match more kinds, not less. It’s almost like every `T` implicitly has -`T: Sized`, and the `?` undoes this default. +This `?Sized`, read as “T may or may not be `Sized`”, allowing us to match both constant size and unsized types. +All generic type parameters implicitly have the `Sized` bound, so `?Sized` can be used to opt-out of the implicit bound. |