Invalid conversions and error messages.

18 Jan 2002

      I wrote a program that GiNaC doesn't like, and it told me so.  (I'm becoming
somewhat of an expert at this)  ;)

#include <ginac/ginac.h>
#include <iostream.h>

using namespace GiNaC;
using namespace std;

int main() {
    symbol a("a");
    ex blah = a;
    numeric blahn = ex_to<numeric>(blah);
    // The line below generates the error:
    // Internal error: statement in file ./float/misc/cl_F_digits.cc, line 25 has been reached!!
    // Please send the authors of the program a description how you produced this error!
    cout << "blahn = " << blahn << endl;
    // If the cout is commented out, the line below generates the error:
    // Internal error: statement in file ./real/elem/cl_R_minusp.cc, line 30 has been reached!!
    // Please send the authors of the program a description how you produced this error!
    if(blahn.is_negative()) { cout << "blahn is negative." << endl; }
}   

Looks to me like a cln error.  But GiNaC should probably throw an exception for
the invalid conversion of "a" to a numeric.

Cheers,
-- Bob

Bob McElrath (rsmcelrath@students.wisc.edu) 
Univ. of Wisconsin at Madison, Department of Physics