Types

Type conversion

• You need to specify the type with : .

• String to Int :

  let a: u32 = "42".parse().expect("Falha!");
  

• &str to String :

  let a = "texto";      // &str
  let b = a.to_string(); // String
  

  let a = String::from("texto");
  

Kinds of types

• Compound Types:

  • Tuples and Arrays.

• Scalar Types:

  • Everything else.

Boolean

fn main() {
    let t = true;
    let f: bool = false;
}

Integers

• .

• " arch " varies depending on the system architecture (32-bit or 64-bit).

  • The primary situation in which you’d use isize  or usize  is when indexing some sort of collection.

• Signed  and unsigned  refer to whether it’s possible for the number to be negative.

Number Literals

• .

• Number literals can also use _  as a visual separator to make the number easier to read.

1_000
1000

Floats

• All floating-point types are signed.

• The default type is f64  because on modern CPUs, it’s roughly the same speed as f32  but is capable of more precision.

fn main() {
    let x = 2.0; // f64
    let y: f32 = 3.0; // f32
}

Char

fn main() {
    let c = 'z';
    let z: char = 'ℤ'; // with explicit type annotation
    let heart_eyed_cat = '😻';
}

• "Your human intuition for what a “character” is may not match up with what a char  is in Rust."