Hex <-> RGB color conversion

hex2rgb.d

module hex2rgb;

struct RGB {
	ubyte r;
	ubyte g;
	ubyte b;

	public this(ubyte r, ubyte g, ubyte b) {
		this.r = r;
		this.g = g;
		this.b = b;
	}

	public this(string strval) {
		import std.conv : to;

		assert(strval.length == 7);

		int value = to!int(strval[1..7], 16);

		this.r = (value & 0xff0000) >> 16;
		this.g = (value & 0x00ff00) >>  8;
		this.b = (value & 0x0000ff);
	}

	string toString() {
		import std.string : format;

		return format("#%06x", (this.r << 16) + (this.g << 8) + this.b);
	}
}

unittest {
	assert(RGB(0, 51, 255).toString == "#0033ff");
	assert(RGB("#0033ff") == RGB(0, 51, 255));
	assert(RGB("#ffffff") == RGB(255, 255, 255));
	assert(RGB("#999999") == RGB(153, 153, 153));
}

version (unittest) {
	void main() {};
}