More 0.7 release notes #7165
More 0.7 release notes #7165
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| * The `main` function is only detected at the topmost level of the crate. | ||
| The `#[main]` attribute is still valid anywhere. | ||
| * Struct fields may no longer be mutable. Use inherited mutability. | ||
| * Oh, but actually you can put `#[mutable]` on a field if you *really* |
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Is this true? I thought that this just turned on some bit about the type information in middle::ty
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Well, it's required if you're going to use unsafe code to hack around the mutability rules. Perhaps it shouldn't be mentioned at all, since it's just an edge case feature.
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But this doesn't mean that this is valid code, right?
struct A {
#[mutable]
a: int
}
fn main() {
let a = A{ a: 3 };
a.a = 4;
}
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I concur, don't even mention the attribute.
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That won't work. It can only be applied to the type (not a field or variant) and all it does is make it not classified as Const (soon to be Freeze). Making it safe is still entirely up to the user, it's just one tool required to make a type like RcMut safe.
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If #[mutable] and #[non_owned] both turn off traits perhaps we can name them similarly, #[non_send], #[non_freeze], etc?
Both of these are added in 0.7. It seems notable that we are providing this way to turn off a feature of the type system, so I'm inclined to mention it.
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OK, updated to reflect this feedback. Thanks.
Fix needless_quesiton_mark false positive changelog: Fix [`needless_question_mark`] false positive where the inner value is implicity dereferenced by the question mark. Fixes rust-lang#7107
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