Rudimentary (buggy) world serialization/deserialization

src/bitmanip.rs

@@ -0,0 +1,56 @@
+use std::ops::{BitAndAssign, BitOrAssign};
+
+use num_traits::PrimInt;
+
+pub fn nth_bit_set<N: PrimInt>(number: N, n: usize) -> bool {
+    (number & (N::one() << n)) != N::zero()
+}
+
+pub fn set_nth_bit<N: PrimInt + BitOrAssign + BitAndAssign>(number: &mut N, n: usize, set: bool) {
+    let mask = N::one() << n;
+    if set {
+        *number |= mask;
+    } else {
+        *number &= !mask;
+    }
+}
+
+#[test]
+fn test_nth_bit_set() {
+    let number: u8 = 0b0100_0100;
+    assert_eq!(nth_bit_set(number, 0), false);
+    assert_eq!(nth_bit_set(number, 1), false);
+    assert_eq!(nth_bit_set(number, 2), true);
+    assert_eq!(nth_bit_set(number, 3), false);
+    assert_eq!(nth_bit_set(number, 4), false);
+    assert_eq!(nth_bit_set(number, 5), false);
+    assert_eq!(nth_bit_set(number, 6), true);
+    assert_eq!(nth_bit_set(number, 7), false);
+    assert_eq!(nth_bit_set(0u64, 0), false);
+    assert_eq!(nth_bit_set(u64::MAX, 63), true);
+}
+
+#[test]
+fn test_set_nth_bit() {
+    let mut number: u8 = 0b0000_0000;
+    set_nth_bit(&mut number, 0, true);
+    assert_eq!(number, 0b0000_0001);
+    set_nth_bit(&mut number, 1, true);
+    assert_eq!(number, 0b0000_0011);
+    set_nth_bit(&mut number, 2, true);
+    assert_eq!(number, 0b0000_0111);
+    set_nth_bit(&mut number, 0, false);
+    assert_eq!(number, 0b0000_0110);
+
+    let mut all_bits_set: u64 = 0;
+    for i in 0..64 {
+        set_nth_bit(&mut all_bits_set, i, true);
+        assert_eq!(nth_bit_set(all_bits_set, i), true);
+    }
+
+    let mut no_bits_set: u64 = u64::MAX;
+    for i in 0..64 {
+        set_nth_bit(&mut no_bits_set, i, false);
+        assert_eq!(nth_bit_set(no_bits_set, i), false);
+    }
+}