Rust Search

Static items

Static items StaticItem -> ItemSafety?[^extern-safety] `static` `mut`? IDENTIFIER `:` Type ( `=` Expression )? `;` [^extern-safety]: The safe and unsafe function qualifiers are only allowed semantically within extern blocks. A static item i...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~3 min read

Constant items

Constant items ConstantItem -> `const` ( IDENTIFIER | `_` ) `:` Type ( `=` Expression )? `;` A constant item is an optionally named constant value which is not associated with a specific memory location in the program. Constants are essenti...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~2 min read

Unions

Unions Union -> `union` IDENTIFIER GenericParams? WhereClause? `{` StructFields? `}` A union declaration uses the same syntax as a struct declaration, except with union in place of struct. A union declaration defines the given name in the t...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~4 min read

Enumerations

Enumerations Enumeration -> `enum` IDENTIFIER GenericParams? WhereClause? `{` EnumVariants? `}` EnumVariants -> EnumVariant ( `,` EnumVariant )* `,`? EnumVariant -> OuterAttribute* Visibility? IDENTIFIER ( EnumVariantTuple | EnumVariantStru...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~5 min read

Structs

Structs Struct -> StructStruct | TupleStruct StructStruct -> `struct` IDENTIFIER GenericParams? WhereClause? ( `{` StructFields? `}` | `;` ) TupleStruct -> `struct` IDENTIFIER GenericParams? `(` TupleFields? `)` WhereClause? `;` StructField...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read

Type aliases

Type aliases TypeAlias -> `type` IDENTIFIER GenericParams? ( `:` Bounds )? WhereClause? ( `=` Type WhereClause?)? `;` A type alias defines a new name for an existing type in the type namespace of the module or block where it is located. Typ...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read

Functions

Functions Function -> FunctionQualifiers `fn` IDENTIFIER GenericParams? `(` FunctionParameters? `)` FunctionReturnType? WhereClause? ( BlockExpression | `;` ) FunctionQualifiers -> `const`? `async`?[^async-edition] ItemSafety?[^extern-quali...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~10 min read

Use declarations

Use declarations UseDeclaration -> `use` UseTree `;` UseTree -> (SimplePath? `::`)? `*` | (SimplePath? `::`)? `{` (UseTree ( `,` UseTree )* `,`?)? `}` | SimplePath ( `as` ( IDENTIFIER | `_` ) )? A use declaration creates one or more local n...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~10 min read

Extern crate declarations

Extern crate declarations ExternCrate -> `extern` `crate` CrateRef AsClause? `;` CrateRef -> IDENTIFIER | `self` AsClause -> `as` ( IDENTIFIER | `_` ) An extern crate declaration specifies a dependency on an external crate. The external cra...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~2 min read

Modules

Modules Module -> `unsafe`? `mod` IDENTIFIER `;` | `unsafe`? `mod` IDENTIFIER `{` InnerAttribute* Item* `}` A module is a container for zero or more items. A module item is a module, surrounded in braces, named, and prefixed with the keywor...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~3 min read

Items

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read

Conditional compilation

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~9 min read

Crates and source files

Crates and source files @root Crate -> InnerAttribute* Item* [!NOTE] Although Rust, like any other language, can be implemented by an interpreter as well as a compiler, the only existing implementation is a compiler, and the language has al...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~3 min read

Procedural macros

Procedural macros Procedural macros allow creating syntax extensions as execution of a function. Procedural macros come in one of three flavors: • Function-like macros - custom!(...) • Derive macros - #[derive(CustomDerive)] • Attribute mac...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~10 min read

Macros by example

Macros by example MacroRulesDefinition -> `macro_rules` `!` IDENTIFIER MacroRulesDef MacroRulesDef -> `(` MacroRules `)` `;` | `[` MacroRules `]` `;` | `{` MacroRules `}` MacroRules -> MacroRule ( `;` MacroRule )* `;`? MacroRule -> MacroMat...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~18 min read

Macros

Macros The functionality and syntax of Rust can be extended with custom definitions called macros. They are given names, and invoked through a consistent syntax: some_extension!(...). There are two ways to define new macros: • Macros by Exa...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read

Tokens

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~20 min read

Whitespace

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read

Comments

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~2 min read

Identifiers

Identifiers IDENTIFIER_OR_KEYWORD -> ( XID_Start | `_` ) XID_Continue* XID_Start -> <`XID_Start` defined by Unicode> XID_Continue -> <`XID_Continue` defined by Unicode> RAW_IDENTIFIER -> `r#` IDENTIFIER_OR_KEYWORD NON_KEYWORD_IDENTIFIER ->...

doc.rust-lang.org The Rust Reference Book 2024-01-01 ~1 min read