Rust datatypes

Literals

'a'        // char
"abc"      // string
1234       // i32
3.14       // f32
true/false // bool

1_000      // == 1000
1.000_000  // == 1.000000

Primitives

Text

string

"abcd"  // string

char

char
'a'    // character (single)

Numbers

implied type	let var = 12;
assigned type	let var: i8 = 12;
type suffix	let var = 12i8;

Integers

• signed integers range is split in two, can be positive/negative
• unsigned integers are positive, and use all available bits
• use radix to calculate max size that can be accomodated with b bits $2^{b}$

// signed integers, by bit-size
i8   //        -128..127
i16  //      -32768..32767
i32  // -2147483648..2147483647
i64  // ...
i128
isize

// unsigned integers, by bit-size
u8   // 0..255
u16  // 0..65535
u36  // 0..4294967295
u64  // ...
u128
usize

Floating Point

f32
f64

Boolean

true
false

Collections

tuples

• tuples are dynamically sized
• tuples can store mixed types
• tuples can contain other tuples

var = (1, "two", 3.14)
var.0  // item at index 1

arrays

• arrays are homogenous
• arrays have a predeterminted/fixed size
• arrays are stored contiguously in memory

// initialization
let var: [i32; 4] = [1, 2, 3, 4];  // declare an array of 4x 32-bit integers
let var: [i32; 4] = [100; 4];      // initialize all 4x ints as 100

// methods
var[0]     // 1
var.len()  // 4

// slices
let foo = &var[1..2];   // [2, 3]
println!("{}", foo[0]); // 2

structs

struct Person { name: String, age: u8 }  // struct
struct Unit                              // unit struct
struct Color(i8, i8, i8);                // tuple-struct