Rust has the following built-in primitive types:

• bool: These are the usual booleans and can be either true or false .
• char: Characters, such as e.
• Integer types: These are characterized by the bit width. Rust supports integers that are up to 128 bits wide:
  

  signed	unsigned
  i8	u8
  i16	u16
  i32	u32
  i64	u64
  i128	u128

• isize: The pointer-sized signed integer type. Equivalent to i32 on 32-bit CPU and i64 on 64-bit CPU.
• usize: The pointer-sized unsigned integer type. Equivalent to i32 on 32-bit CPU and i64 on 64-bit CPU.
• f32: The 32-bit floating point type. Implements the IEEE 754 standard for floating point representation.
• f64: The 64-bit floating point type.
• [T; N]: A fixed-size array, for the element type, T, and the non-negative compile-time constant size N.

• [T]: A dynamically-sized view into a contiguous sequence, for any type T.
• str: String slices, mainly used as a reference, that is, &str.
• (T, U, ..): A finite sequence, (T, U, ..) where T and U can be different types.
• fn(i32) -> i32: A function that takes an i32 and returns an i32. Functions also have a type.