char16

char16 is a two-byte character covering the entire Basic Multilingual Plane (U+0000–U+FFFF) — Latin, Cyrillic, CJK, Arabic, Hebrew, and most common symbols. Like all Rux character types it is an unsigned, non-nullable value type that holds a single code point or raw code unit, and is type-distinct from both integers and strings. Use it when interoperating with UTF-16 APIs; otherwise prefer the default char.

Literals

A character literal is written with single quotes:

let kanji: char16 = '字';  // U+5B57
let star: char16 = '★';   // U+2605
let fire: char16 = '🔥';   // U+1F525 — compile error: out of range for char16

Code points above U+FFFF cannot be represented and produce a compile-time error.

Escape Sequences

The \u{...} escape takes 1–6 hexadecimal digits (braces mandatory); values outside the type's range are rejected at compile time.

Typical Use Cases

• UTF-16 code units
• Interop with Java / C# / Windows wide strings

Comparison

Character types are comparable for both equality and ordering. Ordering follows the numeric value of the underlying code point (code-point order, not locale-aware collation).

let a: char16 = 'a';
let b: char16 = 'b';

let eq = a == b;  // false
let lt = a < b;   // true  (U+0061 < U+0062)

Conversion

Character types are not integers, but they convert explicitly with as.

Widening to a wider char type is implicit and always safe:

let c: char16 = '字';
let wide: char32 = c;   // widening — always valid

Narrowing to a smaller char type is checked at runtime: a value that does not fit triggers a fatal error, so prefer the as? form, which returns null instead:

let wide: char32 = '🔥';              // U+1F525
let narrow = wide as char16;          // fatal error: value > U+FFFF
let safe: char16? = wide as? char16;  // null instead

Conversions to and from the backing integer type are also explicit:

let c: char16 = '★';
let n = c as uint32;      // 0x00002605
let back = n as char16;   // '★'

Char types have no arithmetic operators — cast to the integer type to compute offsets, then cast back:

let c: char16 = 'a';
let next = (c as uint32 + 1) as char16;  // 'b'

String Interop

A single character converts to a one-character String with String::From() or interpolation, and String indexing returns a char by code-point position (not byte offset):

let c: char16 = '★';
let s = String::From(c);        // "★"
let t = "{c}";                 // "★"  (interpolation)
let first: char = "Hello"[0];  // 'H'

Source files are UTF-8; in memory a char is a little-endian unsigned integer of its declared width.

See Also

• char — the default character type
• char8 — the next width down
• char32 — the next width up