id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
10680	Cannot use Eigen vector as state type in integrate?	ilja.j.honkonen@…	karsten	"The program

{{{
#include ""boost/numeric/odeint.hpp""
#include ""Eigen/Core""

using namespace boost::numeric::odeint;

int main()
{
	Eigen::Vector3d state(0, 0, 0);
	integrate(
		[](const auto& state, auto& change, const double /*time*/){
			change = Eigen::Vector3d(1, 0, 0);
		},
		state,
		0.0,
		1.0,
		0.1
	);
	return 0;
}
}}}

does not compile with Apple LLVM version 6.0 (clang-600.0.51) (based on LLVM 3.5svn) using -std=c++1y

{{{
In file included from /Users/iljah/include/boost/numeric/odeint.hpp:67:
/Users/iljah/include/boost/numeric/odeint/integrate/integrate.hpp:59:12: error: no matching function for call to
      'integrate'
    return integrate( system , start_state , start_time , end_time , dt , null_observer() );
           ^~~~~~~~~
odeint1.cpp:9:2: note: in instantiation of function template specialization 'boost::numeric::odeint::integrate<<lambda
      at odeint1.cpp:10:3>, Eigen::Matrix<double, 3, 1, 0, 3, 1>, double>' requested here
        integrate(
        ^
/Users/iljah/include/boost/numeric/odeint/integrate/integrate.hpp:44:28: note: candidate template ignored: disabled by
      'enable_if' [with System = <lambda at odeint1.cpp:10:3>, State = Eigen::Matrix<double, 3, 1, 0, 3, 1>, Time =
      double, Observer = boost::numeric::odeint::null_observer]
typename boost::enable_if< typename has_value_type<State>::type , size_t >::type
                           ^
/Users/iljah/include/boost/numeric/odeint/integrate/integrate.hpp:57:8: note: candidate function template not viable:
      requires 5 arguments, but 6 were provided
size_t integrate( System system , State &start_state , Time start_time , Time end_time , Time dt )
       ^
1 error generated.
}}}

Based on ""disabled by 'enable_if'"" I'd guess the problem is in odeint not Eigen, or this a user error? I get many more errors if the state type is e.g. a std::array of Eigen vectors but I'll create another ticket if that issue persists."	Bugs	closed	To Be Determined	odeint	Boost 1.56.0	Problem	fixed