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mirror of https://github.com/rust-lang/rustlings.git synced 2024-12-12 11:14:55 +02:00
rustlings/exercises/conversions
Taylor Yu c3e7b83178 fix: use trait objects for from_str
Use `Box<dyn error::Error>` to allow solutions to use `?` to propagate 
errors.
2021-04-04 18:56:10 -05:00
..
as_ref_mut.rs chore: Alter whitespace for consistency 2020-07-11 11:50:54 -07:00
from_into.rs feat(from_into) : add test for checking unnecessary trailing value 2021-01-09 00:08:38 +09:00
from_str.rs fix: use trait objects for from_str 2021-04-04 18:56:10 -05:00
README.md feat: Add type conversion and parsing exercises 2019-12-16 09:12:13 -05:00
try_from_into.rs fix: use trait objects for try_from_into 2021-04-04 12:41:32 -05:00
using_as.rs fix(using_as): Add test so that proper type is returned. (#512) 2020-09-07 19:09:27 +02:00

Type conversions

Rust offers a multitude of ways to convert a value of a given type into another type.

The simplest form of type conversion is a type cast expression. It is denoted with the binary operator as. For instance, println!("{}", 1 + 1.0); would not compile, since 1 is an integer while 1.0 is a float. However, println!("{}", 1 as f32 + 1.0) should compile. The exercise using_as tries to cover this.

Rust also offers traits that facilitate type conversions upon implementation. These traits can be found under the convert module. The traits are the following:

Furthermore, the std::str module offers a trait called FromStr which helps with converting strings into target types via the parse method on strings. If properly implemented for a given type Person, then let p: Person = "Mark,20".parse().unwrap() should both compile and run without panicking.

These should be the main ways within the standard library to convert data into your desired types.

Book Sections

These are not directly covered in the book, but the standard library has great documentation for conversions here. The FromStr trait is also covered here.