id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
10127	coordinate_matrix sort() fails on to std::swap	anonymous	Gunter	"Orginally posted here:

http://stackoverflow.com/questions/24228772/c11-compatibility-of-sparse-matrix-implementations

The following program does not compile with gcc 4.8 or clang 3.4 when --std=c++11 is set:

{{{
#include <boost/numeric/ublas/io.hpp>
#include <boost/numeric/ublas/matrix_sparse.hpp>

using namespace boost::numeric::ublas;

int main(int argc, char** argv) {
  coordinate_matrix<int> m1(100, 100, 100);

  for (int i = 0; i < 100; i++)
    m1.insert_element(i,i,i);

  compressed_matrix<int> m2(m1, 100);
}
}}}

We can solve the issue by providing a swap() routine:

{{{
#include <boost/numeric/ublas/io.hpp>
#include <boost/numeric/ublas/matrix_sparse.hpp>

using namespace boost::numeric::ublas;

namespace std {
    template<class M>
    inline
    void swap (boost::numeric::ublas::index_triple<M> i1, boost::numeric::ublas::index_triple<M> i2) {
        i1.swap (i2);
    }
}


int main(int argc, char** argv) {
  coordinate_matrix<int> m1(100, 100, 100);

  for (int i = 0; i < 100; i++)
    m1.insert_element(i,i,i);
  
  compressed_matrix<int> m2(m1, 100);
}
}}}

I am not an expert C++ template programmer, so I am unable to decide what is the cause here, but the C++ reference on std::sort explicitly mentions a swap() method."	Bugs	new	Boost 1.58.0	uBLAS	Boost 1.54.0	Showstopper		c++11,swap,sort,matrix,reference