Structs
Syntax
Struct :
StructStruct
| TupleStructStructStruct :
structIDENTIFIER Generics? WhereClause? ({StructFields?}|;)TupleStruct :
structIDENTIFIER Generics?(TupleFields?)WhereClause?;StructFields :
StructField (,StructField)*,?StructField :
OuterAttribute*
Visibility IDENTIFIER:TypeTupleFields :
TupleField (,TupleField)*,?TupleField :
OuterAttribute*
Visibility Type
A struct is a nominal struct type defined with the keyword struct.
An example of a struct item and its use:
# #![allow(unused_variables)] #fn main() { struct Point {x: i32, y: i32} let p = Point {x: 10, y: 11}; let px: i32 = p.x; #}
A tuple struct is a nominal tuple type, also defined with the keyword
struct. For example:
# #![allow(unused_variables)] #fn main() { struct Point(i32, i32); let p = Point(10, 11); let px: i32 = match p { Point(x, _) => x }; #}
A unit-like struct is a struct without any fields, defined by leaving off the list of fields entirely. Such a struct implicitly defines a constant of its type with the same name. For example:
# #![allow(unused_variables)] #fn main() { struct Cookie; let c = [Cookie, Cookie {}, Cookie, Cookie {}]; #}
is equivalent to
# #![allow(unused_variables)] #fn main() { struct Cookie {} const Cookie: Cookie = Cookie {}; let c = [Cookie, Cookie {}, Cookie, Cookie {}]; #}
The precise memory layout of a struct is not specified. One can specify a
particular layout using the repr attribute.