comprehensive-rust/src/basic-syntax/scalar-types.md

Scalar Types

	Types	Literals
Signed integers	i8, i16, i32, i64, i128, isize	-10, 0, 1_000, 123_i64
Unsigned integers	u8, u16, u32, u64, u128, usize	0, 123, 10_u16
Floating point numbers	f32, f64	3.14, -10.0e20, 2_f32
Strings	&str	"foo", "two\nlines"
Unicode scalar values	char	'a', 'α', '∞'
Booleans	bool	true, false

The types have widths as follows:

• iN, uN, and fN are N bits wide,
• isize and usize are the width of a pointer,
• char is 32 bits wide,
• bool is 8 bits wide.

There are a few syntaxes which are not shown above:

• Raw strings allow you to create a &str value with escapes disabled: r"\n" == "\\\\n". You can embed double-quotes by using an equal amount of # on either side of the quotes:

  fn main() {
      println!(r#"<a href="link.html">link</a>"#);
      println!("<a href=\"link.html\">link</a>");
  }
  

• Byte strings allow you to create a &[u8] value directly:

  fn main() {
      println!("{:?}", b"abc");
      println!("{:?}", &[97, 98, 99]);
  }
  

• All underscores in numbers can be left out, they are for legibility only. So 1_000 can be written as 1000 (or 10_00), and 123_i64 can be written as 123i64.