On 11/2/2010 10:14 AM, Kamil Zubair wrote:
I found a strange error when I try the vec3 sample from proto, my code is like this: <snip>
int main(int argc, const char* argv[]) { Vec3 a(1, 2, 3); Vec3 b(3, 2, 1); Vec3 c; c = b; c.print();
return 0; }
I expected that when c is printed it will display 3, 2, 1 ( the value of b ) but instead it print 0,0,0 like b is never assigned to c. I try this using vs 2010 with boost 1.44 in windows 7 64.
You found a bug in the Vec3 example. The Vec3 class needs a the following copy assign: Vec3 &operator=(Vec3 const &that) { (*this)[0] = that[0]; (*this)[1] = that[1]; (*this)[2] = that[2]; return *this; } Why? A template operator= is never considered for copy assignment, and so it finds the one in proto::extends. That one simply creates an assign tree node which never gets used. Thanks for the report. I'll fix the example. -- Eric Niebler BoostPro Computing http://www.boostpro.com