Document bitoperations.h

src/storm/utility/bitoperations.h

@@ -1,17 +1,30 @@
 #pragma once
 #include <cstddef>
+
 #include "storm/utility/macros.h"
 
+/**
+ * \return 2^n - 1
+ */
 inline size_t smallestIntWithNBitsSet(size_t n) {
     static_assert(sizeof(size_t) == 8, "size_t has wrong size.");
-    STORM_LOG_ASSERT(n < 64, "Input is too large."); // TODO fix this for 32 bit architectures!
+    STORM_LOG_ASSERT(
+        n < 64,
+        "Input is too large.");  // TODO fix this for 32 bit architectures!
     if (n == 0) return 0;
     return (1 << n) - 1;
 }
 
+/**
+ * The next bit permutation in a lexicographical sense.
+ *
+ * Example: 00010011, 00010101, 00010110, 00011001,
+ * 00011010, 00011100, 00100011, and so forth
+ *
+ * From https://graphics.stanford.edu/~seander/bithacks.html#NextBitPermutation
+ */
 inline size_t nextBitPermutation(size_t v) {
     if (v == 0) return static_cast<size_t>(0);
-    // From https://graphics.stanford.edu/~seander/bithacks.html#NextBitPermutation
     size_t t = (v | (v - 1)) + 1;
     return t | ((((t & -t) / (v & -v)) >> 1) - 1);
 }