+ return x;
+}
+
+/* An attempt at a useful 1-bit hash function. Has not been analyzed for
+ * quality. */
+static inline uint32_t hash_boolean(bool x, uint32_t basis)
+{
+ const uint32_t P0 = 0xc2b73583; /* This is hash_int(1, 0). */
+ const uint32_t P1 = 0xe90f1258; /* This is hash_int(2, 0). */
+ return (x ? P0 : P1) ^ HASH_ROT(basis, 1);