当我尝试编译以下代码时,我面临错误
在'struct result_of_make_controlled>'的实例化中:54:53:替换'template typename result_of_make_controlled :: type make_controlled(typename Stepper :: value_type,typename Stepper :: value_type,const Stepper&)[with Stepper = runge_kutta_dopri5]'69 :60:从这里要求49:54:错误:'struct get_controller>中没有名为'type'的类型'typedef typename get_controller <Stepper> :: type type;
class explicit_error_stepper_fsal_base
{
public:
typedef double state_type;
typedef double value_type;
};
template<class State>
class runge_kutta_dopri5
: public explicit_error_stepper_fsal_base
{
public :
typedef explicit_error_stepper_fsal_base stepper_base_type;
typedef typename stepper_base_type::value_type value_type;//#
runge_kutta_dopri5( )
{ }
};
template< class Stepper > struct get_controller { };
// default controller factory
template< class Stepper , class Controller >
struct controller_factory
{
Controller operator()(
typename Stepper::value_type abs_error ,
typename Stepper::value_type rel_error ,
const Stepper &stepper )
{
return Controller( abs_error , rel_error , stepper );
}
};
template< class Stepper >
struct result_of_make_controlled
{
typedef typename get_controller< Stepper >::type type;
};
template< class Stepper >
typename result_of_make_controlled< Stepper >::type make_controlled(
typename Stepper::value_type abs_error ,
typename Stepper::value_type rel_error ,
const Stepper & stepper = Stepper() )
{
typedef Stepper stepper_type;
typedef typename result_of_make_controlled< stepper_type >::type controller_type;
typedef controller_factory< stepper_type , controller_type > factory_type;
factory_type factory;
return factory( abs_error , rel_error , stepper );
}
typedef double state_type;
typedef runge_kutta_dopri5<state_type> stepper_type;
typedef decltype(make_controlled(1E-10,1E-10,stepper_type())) controlled_stepper_type;
int main()
{
return 0;
}
我假设它需要在结构 get_controller
内查找名为 type
的类型,而它是空的并导致错误 . 我不明白的是,为什么在github boost library的原始源代码中,编译器端没有问题?
1 回答
相关的boost Headers 为
get_controller
提供了特定步进器的部分特化 . 您的代码不会这样做 . For example: