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Statics may sometimes inline. #323

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May 3, 2018
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Statics may sometimes inline. #323

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19 changes: 10 additions & 9 deletions src/items/static-items.md
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Expand Up @@ -6,18 +6,17 @@
> `=` [_Expression_] `;`

A *static item* is similar to a [constant], except that it represents a precise
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This paragraph is just a list of properties, which makes me feel like it does not flow very well. I'm not sure the best way to address that; perhaps splitting the things about lifetimes into a separate paragraph would help, or adding more connective prose?

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It definitely doesn't flow well. It reads almost like a list but without the bullet points. Should probably be addressed, but not as part of this issue.

memory location in the program. A static is never "inlined" at the usage site,
and all references to it refer to the same memory location. Static items have
the `static` lifetime, which outlives all other lifetimes in a Rust program.
Static items may be placed in read-only memory if the type is not [interior
mutable]. Static items do not call `drop` at the end of the program.
memory location in the program. All references to the static refer to the same
memory location. Static items have the `static` lifetime, which outlives all
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Should this be 'static lifetime instead?

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'static is the static lifetime. I think both could work there.

other lifetimes in a Rust program. Non-`mut` static items that contain a type
that is not [interior mutable] may be placed in read-only memory. Static items
do not call [`drop`] at the end of the program.

All access to a static is safe, but there are a number of restrictions on
statics:

* The type must have the `Sync` trait bound to allow thread-safe access.
* Statics allow using paths to statics in the
[constant-expression](expressions.html#constant-expressions) used to
* Statics allow using paths to statics in the [constant-expression] used to
initialize them, but statics may not refer to other statics by value, only
through a reference.
* Constants cannot refer to statics.
Expand All @@ -33,7 +32,7 @@ modifications to a mutable static are safe with respect to other threads
running in the same process.

Mutable statics are still very useful, however. They can be used with C
libraries and can also be bound from C libraries (in an `extern` block).
libraries and can also be bound from C libraries in an `extern` block.

```rust
# fn atomic_add(_: &mut u32, _: u32) -> u32 { 2 }
Expand Down Expand Up @@ -66,10 +65,12 @@ item. Constants should, in general, be preferred over statics unless one of the
following are true:

* Large amounts of data are being stored
* The single-address or non-inlining property of statics is required.
* The single-address property of statics is required.
* Interior mutability is required.

[constant]: items/constant-items.html
[`drop`]: destructors.html
[constant expression]: expressions.html#constant-expressions
[interior mutable]: interior-mutability.html
[IDENTIFIER]: identifiers.html
[_Type_]: types.html
Expand Down