crosvm/bit_field/tests/test_enum.rs
Jingkui Wang 85fa41f7b2 implement bitfield for enum with a width
If we know the width of an enum type, we don't need 'power of 2' number
of variants.

BUG=None
TEST=cargo test

Change-Id: I8148b28f86bb8e4fd4f67d8a6382fc713dad1439
Reviewed-on: https://chromium-review.googlesource.com/1530455
Commit-Ready: Jingkui Wang <jkwang@google.com>
Tested-by: Jingkui Wang <jkwang@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: David Tolnay <dtolnay@chromium.org>
2019-03-28 19:04:03 -07:00

50 lines
1,018 B
Rust

extern crate bit_field;
use bit_field::*;
#[bitfield]
#[derive(Debug, PartialEq)]
enum TwoBits {
Zero = 0b00,
One = 0b01,
Two = 0b10,
Three = 0b11,
}
#[bitfield]
#[bits = 3]
#[derive(Debug, PartialEq)]
enum ThreeBits {
Zero = 0b00,
One = 0b01,
Two = 0b10,
Three = 0b111,
}
#[bitfield]
struct Struct {
prefix: BitField1,
two_bits: TwoBits,
three_bits: ThreeBits,
suffix: BitField2,
}
#[test]
fn test_enum() {
let mut s = Struct::new();
assert_eq!(s.get(0, 8), 0b_0000_0000);
assert_eq!(s.get_two_bits(), TwoBits::Zero);
s.set_two_bits(TwoBits::Three);
assert_eq!(s.get(0, 8), 0b_0000_0110);
assert_eq!(s.get_two_bits(), TwoBits::Three);
s.set(0, 8, 0b_1010_1010);
// ^^ TwoBits
// ^^_^ Three Bits.
assert_eq!(s.get_two_bits(), TwoBits::One);
assert_eq!(s.get_three_bits().unwrap_err().raw_val(), 0b101);
s.set_three_bits(ThreeBits::Two);
assert_eq!(s.get(0, 8), 0b_1001_0010);
}