docs: update to avoid mention of const.

This commit is contained in:
Graydon Hoare 2013-03-22 16:45:54 -07:00
parent 62c1f049f8
commit b481829306
3 changed files with 22 additions and 21 deletions

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@ -617,8 +617,8 @@ each of which may have some number of [attributes](#attributes) attached to it.
## Items
~~~~~~~~ {.ebnf .gram}
item : mod_item | fn_item | type_item | enum_item
| const_item | trait_item | impl_item | foreign_mod_item ;
item : mod_item | fn_item | type_item | struct_item | enum_item
| static_item | trait_item | impl_item | foreign_mod_item ;
~~~~~~~~
An _item_ is a component of a crate; some module items can be defined in crate
@ -627,7 +627,7 @@ crate by a nested set of [modules](#modules). Every crate has a single
"outermost" anonymous module; all further items within the crate have
[paths](#paths) within the module tree of the crate.
Items are entirely determined at compile-time, remain constant during
Items are entirely determined at compile-time, generally remain fixed during
execution, and may reside in read-only memory.
There are several kinds of item:
@ -637,7 +637,7 @@ There are several kinds of item:
* [type definitions](#type-definitions)
* [structures](#structures)
* [enumerations](#enumerations)
* [constants](#constants)
* [static items](#static-items)
* [traits](#traits)
* [implementations](#implementations)
@ -1091,21 +1091,23 @@ a = Cat{ name: ~"Spotty", weight: 2.7 };
In this example, `Cat` is a _struct-like enum variant_,
whereas `Dog` is simply called an enum variant.
### Constants
### Static items
~~~~~~~~ {.ebnf .gram}
const_item : "const" ident ':' type '=' expr ';' ;
static_item : "static" ident ':' type '=' expr ';' ;
~~~~~~~~
A *constant* is a named value stored in read-only memory in a crate.
The value bound to a constant is evaluated at compile time.
Constants are declared with the `static` keyword.
A constant item must have an expression giving its definition.
The definition expression of a constant is limited to expression forms that can be evaluated at compile time.
A *static item* is a named _constant value_ stored in the global data section of a crate.
Immutable static items are stored in the read-only data section.
The constant value bound to a static item is, like all constant values, evaluated at compile time.
Static items have the `static` lifetime, which outlives all other lifetimes in a Rust program.
Static items are declared with the `static` keyword.
A static item must have a _constant expression_ giving its definition.
Constants must be explicitly typed. The type may be ```bool```, ```char```, a number, or a type derived from those primitive types.
The derived types are borrowed pointers, static arrays, tuples, and structs.
Borrowed pointers must be have the `'static` lifetime.
Static items must be explicitly typed.
The type may be ```bool```, ```char```, a number, or a type derived from those primitive types.
The derived types are borrowed pointers with the `'static` lifetime,
fixed-size arrays, tuples, and structs.
~~~~
static bit1: uint = 1 << 0;
@ -1456,7 +1458,7 @@ The declared names may denote new slots or new items.
An _item declaration statement_ has a syntactic form identical to an
[item](#items) declaration within a module. Declaring an item -- a function,
enumeration, type, constant, trait, implementation or module -- locally
enumeration, structure, type, static, trait, implementation or module -- locally
within a statement block is simply a way of restricting its scope to a narrow
region containing all of its uses; it is otherwise identical in meaning to
declaring the item outside the statement block.

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@ -468,11 +468,10 @@ overwritten for the duration of the borrow. In fact, the compiler
would accept the example we gave earlier. The example is safe because
the shape pointer has type `&Shape`, which means "borrowed pointer to
immutable memory containing a `shape`". If, however, the type of that
pointer were `&const Shape` or `&mut Shape`, then the ref binding
would be ill-typed. Just as with unique boxes, the compiler will
permit `ref` bindings into data owned by the stack frame even if the
data are mutable, but otherwise it requires that the data reside in
immutable memory.
pointer were `&mut Shape`, then the ref binding would be ill-typed.
Just as with unique boxes, the compiler will permit `ref` bindings
into data owned by the stack frame even if the data are mutable,
but otherwise it requires that the data reside in immutable memory.
# Returning borrowed pointers

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@ -234,7 +234,7 @@ while count < 10 {
Although Rust can almost always infer the types of local variables, you
can specify a variable's type by following it with a colon, then the type
name. Constants, on the other hand, always require a type annotation.
name. Static items, on the other hand, always require a type annotation.
~~~~
static monster_factor: float = 57.8;