X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Futils.h;h=1cac625624501ab1725d870afbe98ac0a469fd01;hp=ebfc9804314a789d6657609ac1b80a9942a03a0c;hb=d7c5ca75b0fc9e58a8676681e3801869e47ad911;hpb=090348bcd9ac2104e1e387430aecd5c8b7289633

diff --git a/ginac/utils.h b/ginac/utils.h
index ebfc9804..1cac6256 100644
--- a/ginac/utils.h
+++ b/ginac/utils.h
@@ -44,6 +44,13 @@ class dunno {};
 
 unsigned log2(unsigned n);
 
+/** Rotate bits of unsigned value by one bit to the left.
+  * This can be necesary if the user wants to define its own hashes. */
+inline unsigned rotate_left(unsigned n)
+{
+	return (n & 0x80000000U) ? (n << 1 | 0x00000001U) : (n << 1);
+}
+
 /** Compare two pointers (just to establish some sort of canonical order).
  *  @return -1, 0, or 1 */
 template <class T>