diff options
Diffstat (limited to 'library/std/src')
| -rw-r--r-- | library/std/src/keyword_docs.rs | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/library/std/src/keyword_docs.rs b/library/std/src/keyword_docs.rs index 54ce0e7b831..a4bbb18da59 100644 --- a/library/std/src/keyword_docs.rs +++ b/library/std/src/keyword_docs.rs @@ -102,7 +102,9 @@ mod break_keyword {} #[doc(keyword = "const")] // -/// Compile-time constants and deterministic functions. +/// Compile-time constants and compile-time evaluable functions. +/// +/// ## Compile-time constants /// /// Sometimes a certain value is used many times throughout a program, and it can become /// inconvenient to copy it over and over. What's more, it's not always possible or desirable to @@ -145,15 +147,28 @@ mod break_keyword {} /// /// Constants, like statics, should always be in `SCREAMING_SNAKE_CASE`. /// +/// For more detail on `const`, see the [Rust Book] or the [Reference]. +/// +/// ## Compile-time evaluable functions +/// +/// The other main use of the `const` keyword is in `const fn`. This marks a function as being +/// callable in the body of a `const` or `static` item and in array initializers (commonly called +/// "const contexts"). `const fn` are restricted in the set of operations they can perform, to +/// ensure that they can be evaluated at compile-time. See the [Reference][const-eval] for more +/// detail. +/// +/// Turning a `fn` into a `const fn` has no effect on run-time uses of that function. +/// +/// ## Other uses of `const` +/// /// The `const` keyword is also used in raw pointers in combination with `mut`, as seen in `*const /// T` and `*mut T`. More about `const` as used in raw pointers can be read at the Rust docs for the [pointer primitive]. /// -/// For more detail on `const`, see the [Rust Book] or the [Reference]. -/// /// [pointer primitive]: primitive.pointer.html /// [Rust Book]: /// ../book/ch03-01-variables-and-mutability.html#differences-between-variables-and-constants /// [Reference]: ../reference/items/constant-items.html +/// [const-eval]: ../reference/const_eval.html mod const_keyword {} #[doc(keyword = "continue")] |