X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fex.h;h=f5008a0f6edd2d2121d61f6efd0f12d4570bfaa4;hp=60d4080c7d7cdeaccad22f9baa7cacc2f6464dfd;hb=52c44ffaee28a70b6df3280c3354ee4241473b14;hpb=12fefbca9b424cb8e9ae05d83883b96e17c7b96e

diff --git a/ginac/ex.h b/ginac/ex.h
index 60d4080c..f5008a0f 100644
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -3,7 +3,7 @@
  *  Interface to GiNaC's light-weight expression handles. */
 
 /*
- *  GiNaC Copyright (C) 1999-2008 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2011 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
@@ -20,19 +20,23 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#ifndef __GINAC_EX_H__
-#define __GINAC_EX_H__
+#ifndef GINAC_EX_H
+#define GINAC_EX_H
 
+#include "basic.h"
+#include "ptr.h"
+
+#include <functional>
 #include <iosfwd>
 #include <iterator>
-#include <functional>
 #include <stack>
 
-#include "basic.h"
-#include "ptr.h"
-
 namespace GiNaC {
-
+#ifdef _MSC_VER
+  // MSVC produces a different symbol for _ex0 when it is declared inside   
+  // ex::is_zero() than when it is declared at top level as follows
+  extern const ex _ex0;
+#endif
 
 /** Helper class to initialize the library.  There must be one static object
  *  of this class in every object file that makes use of our flyweights in
@@ -43,6 +47,7 @@ namespace GiNaC {
  *
  *  @see utils.cpp */
 class library_init {
+	static void init_unarchivers();
 public:
 	library_init();
 	~library_init();
@@ -204,7 +209,12 @@ public:
 	// comparison
 	int compare(const ex & other) const;
 	bool is_equal(const ex & other) const;
-	bool is_zero() const { extern const ex _ex0; return is_equal(_ex0); }
+	bool is_zero() const { 
+#ifndef _MSC_VER
+	  extern const ex _ex0;
+#endif
+	  return is_equal(_ex0); 
+	}
 	bool is_zero_matrix() const;
 	
 	// symmetry
@@ -975,4 +985,4 @@ inline void iter_swap(list<GiNaC::ex>::iterator i1, list<GiNaC::ex>::iterator i2
 
 } // namespace std
 
-#endif // ndef __GINAC_EX_H__
+#endif // ndef GINAC_EX_H