diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/doc/book/unsized-types.md | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/doc/book/unsized-types.md b/src/doc/book/unsized-types.md index 73b90355e4f..a23470d39fa 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 bound syntax, `?Sized`: ```rust struct Foo<T: ?Sized> { @@ -55,6 +55,7 @@ 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`”, which allows us to match +both sized and unsized types. All generic type parameters implicitly +have the `Sized` bound, so the `?Sized` can be used to opt-out of the implicit +bound. |