- removed manual basepointer-fiddling in construct-on-first-use objects

[ginac.git] / ginac / constant.h

diff --git a/ginac/constant.h b/ginac/constant.h
index bf85b382d6c5b38dc2e4ddc5ab89544c2209420d..bdd8d69e79d16b3a5e1612a167341d19b6786627 100644 (file)
--- a/ginac/constant.h
+++ b/ginac/constant.h
@@ -46,7 +46,7 @@ public:
        constant(const std::string & initname, evalffunctype efun = 0, const std::string & texname = std::string());
        constant(const std::string & initname, const numeric & initnumber, const std::string & texname = std::string());
        
-       // functions overriding virtual functions from bases classes
+       // functions overriding virtual functions from base classes
 public:
        void print(const print_context & c, unsigned level = 0) const;
        int degree(const ex & s) const;
@@ -80,11 +80,20 @@ extern const constant Catalan;
 extern const constant Euler;
 
 // utility functions
+
+/** Return the constant object handled by an ex.  Deprecated: use ex_to<constant>().
+ *  This is unsafe: you need to check the type first. */
 inline const constant &ex_to_constant(const ex &e)
 {
        return static_cast<const constant &>(*e.bp);
 }
 
+/** Specialization of is_exactly_a<constant>(obj) for constant objects. */
+template<> inline bool is_exactly_a<constant>(const basic & obj)
+{
+       return obj.tinfo()==TINFO_constant;
+}
+
 } // namespace GiNaC
 
 #endif // ndef __GINAC_CONSTANT_H__