X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fidx.cpp;h=3beb3ac778a9f1108c37189189269ddc4267e8e4;hp=5739f80e492faa28999a78cae4fc85efed393065;hb=da64e515abf7243bc4c84ca3631470931c4e6691;hpb=79e49016f3a732fe1758bc3efd10f0727862017c

diff --git a/ginac/idx.cpp b/ginac/idx.cpp
index 5739f80e..3beb3ac7 100644
--- a/ginac/idx.cpp
+++ b/ginac/idx.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's indices. */
 
 /*
- *  GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <iostream>
@@ -41,7 +41,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(idx, basic,
 
 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(varidx, idx,
   print_func<print_context>(&varidx::do_print).
-  // print_latex inherited from idx
+  print_func<print_latex>(&varidx::do_print_latex).
   print_func<print_tree>(&varidx::do_print_tree))
 
 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(spinidx, varidx,
@@ -242,11 +242,16 @@ ex idx::op(size_t i) const
 
 ex idx::map(map_function & f) const
 {
-	idx *copy = duplicate();
-	copy->setflag(status_flags::dynallocated);
-	copy->clearflag(status_flags::hash_calculated);
-	copy->value = f(value);
-	return *copy;
+	const ex &mapped_value = f(value);
+	if (are_ex_trivially_equal(value, mapped_value))
+		return *this;
+	else {
+		idx *copy = duplicate();
+		copy->setflag(status_flags::dynallocated);
+		copy->clearflag(status_flags::hash_calculated);
+		copy->value = mapped_value;
+		return *copy;
+	}
 }
 
 /** Returns order relation between two indices of the same type. The order