- Fixed an assertion-thinko in matrix::fraction_free_elimination().

[ginac.git] / ginac / utils.h

diff --git a/ginac/utils.h b/ginac/utils.h
index 755881a1f787b180ea6d1169cc67689e3c3b0c2a..2aff369f9165e3eebbdff17b01f5bb7736463484 100644 (file)
--- a/ginac/utils.h
+++ b/ginac/utils.h
@@ -26,6 +26,7 @@
 
 #include <strstream>
 #include <string>
+#include <stdexcept>
 #include "config.h"
 #include "assertion.h"
 
@@ -33,19 +34,32 @@
 namespace GiNaC {
 #endif // ndef NO_NAMESPACE_GINAC
 
+// This should be obsoleted once <sstream> is widely available.
 template<class T>
-string ToString(T const & t)
+std::string ToString(const T & t)
 {
     char buf[256];
-    ostrstream(buf,sizeof(buf)) << t << ends;
+    std::ostrstream(buf,sizeof(buf)) << t << std::ends;
     return buf;
 }
 
-/** Exception thrown by classes which provide their own series expansion to
- *  signal that ordinary Taylor expansion is safe. */
+/** Exception class thrown by classes which provide their own series expansion
+ *  to signal that ordinary Taylor expansion is safe. */
 class do_taylor {};
 
+/** Exception class thrown when a singularity is encountered. */
+class pole_error : public std::domain_error {
+public:
+    explicit pole_error(const std::string& what_arg, int degree);
+    int degree(void) const;
+private:
+    int deg;
+};
+
+// some compilers (e.g. cygwin) define a macro log2, causing confusion
+#ifndef log2
 unsigned log2(unsigned n);
+#endif
 
 int compare_pointers(const void * a, const void * b);
 
@@ -138,6 +152,26 @@ OutputIterator mymerge3(InputIterator1 first1, InputIterator1 last1,
     }
 }
 
+// Compute the sign of a permutation of a vector of things.
+template <typename T>
+int permutation_sign(std::vector<T> s)
+{
+    if (s.size() < 2)
+        return 0;
+    int sigma = 1;
+    for (typename std::vector<T>::iterator i=s.begin(); i!=s.end()-1; ++i) {
+        for (typename std::vector<T>::iterator j=i+1; j!=s.end(); ++j) {
+            if (*i == *j)
+                return 0;
+            if (*i > *j) {
+                iter_swap(i,j);
+                sigma = -sigma;
+            }
+        }
+    }
+    return sigma;
+}
+
 // Collection of `construct on first use' wrappers for safely avoiding
 // internal object replication without running into the `static
 // initialization order fiasco'.  This chest of numbers helps speed up
@@ -151,6 +185,8 @@ const numeric & _num_120(void);   // -120
 const ex & _ex_120(void);
 const numeric & _num_60(void);    // -60
 const ex & _ex_60(void);
+const numeric & _num_48(void);    // -48
+const ex & _ex_48(void);
 const numeric & _num_30(void);    // -30
 const ex & _ex_30(void);
 const numeric & _num_25(void);    // -25
@@ -237,6 +273,8 @@ const numeric & _num25(void);     //  25
 const ex & _ex25(void);
 const numeric & _num30(void);     //  30
 const ex & _ex30(void);
+const numeric & _num48(void);     //  48
+const ex & _ex48(void);
 const numeric & _num60(void);     //  60
 const ex & _ex60(void);
 const numeric & _num120(void);    //  120