Re: [GiNaC-devel] [GiNaC-list] multiplying a matrix with 0 makes it become a scalar 0

Dear all, concerning this question from the GiNaC-list: dummy-address@web.de schrieb:

cout << "(3*blah).evalm(): " << (3*blah).evalm() << endl; // output: // [[3*a], [3*b], [3*c]]

cout << "0*blah: " << 0*blah << endl; // output: // 0

seems to be a bug, and a rather old one (2000/2001). My only idea at the moment is to check explicitly for matrices in the epvector (mul.cpp lines 428-430) which is kind of stupid. Or we could introduce another info_flag for non-scalar objects (set by matrix then) and check for that flag? Any other ideas? Regards, Jens