^{Syntax}

TupleExpression:

`(`

`)`

|`(`

(Expression`,`

)^{+}Expression^{?}`)`

Tuples are written by enclosing zero or more comma-separated expressions in parentheses. They are used to create tuple-typed values.

# #![allow(unused_variables)] #fn main() { (0.0, 4.5); ("a", 4usize, true); (); #}

You can disambiguate a single-element tuple from a value in parentheses with a comma:

# #![allow(unused_variables)] #fn main() { (0,); // single-element tuple (0); // zero in parentheses #}

^{Syntax}

TupleIndexingExpression:

Expression`.`

TUPLE_INDEX

Tuples and struct tuples can be indexed using the number corresponding to the position of the field. The index must be written as a decimal literal with no underscores or suffix. Tuple indexing expressions also differ from field expressions in that they can unambiguously be called as a function. In all other aspects they have the same behavior.

# #![allow(unused_variables)] #fn main() { # struct Point(f32, f32); let pair = (1, 2); assert_eq!(pair.1, 2); let unit_x = Point(1.0, 0.0); assert_eq!(unit_x.0, 1.0); #}

© 2010 The Rust Project Developers

Licensed under the Apache License, Version 2.0 or the MIT license, at your option.

https://doc.rust-lang.org/reference/expressions/tuple-expr.html