Macro hex

macro_rules! hex {
    ($($tt:tt)+) => { ... };
}

Hexadecimal color literal.

Syntax

[#|0x]RRGGBB[AA] or [#|0x]RGB[A].

An optional prefix # or 0x is supported, after the prefix a hexadecimal integer literal is expected. The literal can be separated using _. No integer type suffix is allowed.

The literal is a sequence of 3 or 4 bytes (red, green, blue and alpha). If the sequence is in pairs each pair is a byte [00..=FF]. If the sequence is in single characters this is a shorthand that repeats the character for each byte, e.g. #012F equals #001122FF.

Examples

let red = hex!(#FF0000);
let green = hex!(#00FF00);
let blue = hex!(#0000FF);
let red_half_transparent = hex!(#FF00007F);

assert_eq!(red, hex!(#F00));
assert_eq!(red, hex!(0xFF_00_00));
assert_eq!(red, hex!(FF_00_00));