uint8

PropertyValue
Size1 byte (8 bits)
Minimum value0
Maximum value28−1 = 255
Literal suffixu8
RepresentationBinary, wraps modulo 28
Hardware supportNative on all supported targets

uint8 is the canonical byte type — an unsigned fixed-width integer whose size is identical on every target platform. It stores non-negative values in plain binary and wraps modulo 28 on overflow. The compiler-provided alias byte names this exact type and reads more naturally in raw-memory contexts.

Literals

let a: uint8 = 255;  // explicit annotation
let b = 0xFFu8;      // type suffix, hex

If a literal value does not fit in uint8, the compiler emits an error at compile time. See Literals for decimal, hexadecimal, octal, and binary forms.

Typical Use Cases

  • Raw byte values and binary protocol fields
  • Pixel colour channels
  • Buffers for I/O and serialisation

Arithmetic

OperatorDescriptionCompound
+Addition+=
-Subtraction-=
*Multiplication*=
/Division/=
%Remainder%=
**Exponentiationn/a
let a: uint8 = 10;
let b: uint8 = 3;

let sum  = a + b;   // 13
let quot = a / b;   // 3   truncates toward zero
let rem  = a % b;   // 1   always non-negative

Division truncates toward zero. Because unsigned values are never negative, both the quotient and the remainder are always non-negative.

Overflow. Unsigned arithmetic wraps modulo 28 in both debug and release builds — it never triggers a fatal error. Subtracting past zero wraps to a large value rather than going negative (0 - 1 yields 255), so prefer a signed type for any value that can legitimately fall below zero.

Comparison

OperatorDescriptionResult
==Equalbool
!=Not equalbool
<Less thanbool
<=Less than or equalbool
>Greater thanbool
>=Greater than or equalbool

Both operands must have the same type. Comparing uint8 with another integer type — or with a signed type such as int8 — is a compile-time error; cast one operand explicitly first.

Shift and Bitwise

Right shift on an unsigned value is logical: the vacated high bits are filled with zeros, never a sign bit. Left shift likewise fills the vacated low bits with zeros.

let u: uint8 = 20;  // 0b00010100
let l = u << 2;     // 80   logical left shift
let r = u >> 2;     //  5   logical right shift, zero-filled

Unsigned types are the natural home for bit manipulation; the operators & (AND), | (OR), ^ (XOR), and ~ (NOT) are all defined.

let a: uint8 = 0b1100;  // 12
let b: uint8 = 0b1010;  // 10
let and = a & b;        // 0b1000 = 8
let or  = a | b;        // 0b1110 = 14
let xor = a ^ b;        // 0b0110 = 6

Conversion

Rux performs no implicit numeric conversions — every conversion uses the as operator. Widening to a wider type zero-extends, preserving the value; a same-width unsigned↔signed cast reinterprets the bit pattern.

let x: uint8 = 200;
let wide = x as uint32;  // 200   zero-extended, value preserved
let s    = x as int8;    // -56   same width, bits reinterpreted

See Also