unpackDouble method
Unpack value if it exist. Otherwise returns null
.
Throws FormatException if value is not a Double.
Implementation
double? unpackDouble() {
final b = _d.getUint8(_offset);
double? v;
if (b == 0xca) {
v = _d.getFloat32(++_offset);
_offset += 4;
} else if (b == 0xcb) {
v = _d.getFloat64(++_offset);
_offset += 8;
} else if (b == 0xc0) {
v = null;
_offset += 1;
} else {
throw _formatException('double', b);
}
return v;
}