From: Chris Dams <Chris.Dams@mi.infn.it>
Date: Fri, 7 Jul 2006 13:35:29 +0000 (+0000)
Subject: Allow, optionally, indices to be substituted by things that are not indices.
X-Git-Tag: release_1-4-0~82
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=7e68cf1c0515b0397a49a13f2f08decae7509af1

Allow, optionally, indices to be substituted by things that are not indices.
---

diff --git a/ginac/flags.h b/ginac/flags.h
index 6cf3ea94..8ef1c0ac 100644
--- a/ginac/flags.h
+++ b/ginac/flags.h
@@ -52,7 +52,11 @@ public:
 		subs_algebraic = 0x0002,  // for backwards compatibility
 		pattern_is_product = 0x0004,     ///< used internally by expairseq::subschildren()
 		pattern_is_not_product = 0x0008, ///< used internally by expairseq::subschildren()
-		no_index_renaming = 0x0010
+		no_index_renaming = 0x0010,
+		// To indicate that we want to substitue an index by something that is
+		// is not an index. Without this flag the index value would be
+		// substituted in that case.
+		really_subs_idx = 0x0020
 	};
 };
 
diff --git a/ginac/idx.cpp b/ginac/idx.cpp
index e531f0f3..73af6aac 100644
--- a/ginac/idx.cpp
+++ b/ginac/idx.cpp
@@ -365,7 +365,7 @@ ex idx::subs(const exmap & m, unsigned options) const
 	if (it != m.end()) {
 
 		// Substitution index->index
-		if (is_a<idx>(it->second))
+		if (is_a<idx>(it->second) || (options & subs_options::really_subs_idx))
 			return it->second;
 
 		// Otherwise substitute value