Re: [Boost-users] [boost-users][Container] Compilation error using new "static_vector".

2013/7/19 Jupp Tscheak

Hello boost users,

Please consider the following example:

[code] #include "CGAL/Cartesian.h" #include "CGAL/Polygon_2.h"

#include "boost/container/static_vector.hpp"

typedef CGAL::Cartesian<double> Kernel; typedef Kernel::Point_2 Point2d; typedef CGAL::Polygon_2 > Polygon2d;

Polygon2d p; p = Polygon2d(); [/code]

Compiling this code snippet with GCC results in following error message:

[error] error: no match for 'operator=' in 'p = CGAL::Polygon_2, 100u> >((*(const Traits*)(& CGAL::Polygon_2, 100u> >::Traits())))' note: candidate is: CGAL-4.2/include/CGAL/Polygon_2.h:68:7: note: CGAL::Polygon_2, 100u> >& CGAL::Polygon_2, 100u> >::operator=(CGAL::Polygon_2, 100u> >&) CGAL-4.2/include/CGAL/Polygon_2.h:68:7: note: no known conversion for argument 1 from 'sensor::Polygon2d {aka CGAL::Polygon_2, 100u> >}' to 'CGAL::Polygon_2, 100u> >&' [/error]

I apologize for this concrete example using CGAL, but maybe someone has advice for me?

Hello Jupp, I don't know anything about CGAL, but I have a guess for you, where I assume you're *not* in C++11 mode. I think I saw a similar error with my structures and mingw-4.7. Please see this example (warning: it's out of my head, not tested): struct X { static_vector v; }; int main() { X x, y; x = y; // similar compile error } If you get a similar error compiling the example above, I believe I can explain it. I looks to me like the fault of move emulation in static_vector. I'm not sure if it's a bug in static_vector, or if that's the cost of using Boost.Move, but I remember writing my own operator= in struct X helped: struct X { static_vector v; X& operator=( X const& x ) { v = x.v; return *this; } }; I think this is needed, because due to using Boost.Move in emulation mode static_vector defines static_vector& operator=(static_vector&); // note: non-const arg so the auto-generated operaotr= in X also takes a non-const HTH, Kris