Is it possible to fusion-adapt the base class as if it where a member?
First this is the documentation example, side-by-side with the new case:
#include <boost/fusion/adapted/struct/adapt_struct.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
struct employee{
std::string name;
int age;
};
BOOST_FUSION_ADAPT_STRUCT(
employee,
(std::string, name)
(int, age))
struct employee2 : std::string{
int age;
};
BOOST_FUSION_ADAPT_STRUCT(
employee2,
(std::string, name) ???
(int, age))
int main(){}
What should I put in the line with the ???
.
Currently the only solution I found is to do this, but 1) I have to make all members getter and setter functions 2) seems an overkill.
#include <boost/fusion/adapted/adt/adapt_adt.hpp>
struct employee2 : std::string{
int age;
void set_base(std::string const& age_){std::string::operator=(age_);}
std::string const& get_base() const{return static_cast<std::string const&>(*this);}
void set_age(int const& age_){age = age_;}
int const& get_age() const{return age;}
};
BOOST_FUSION_ADAPT_ADT(
employee2,
(std::string, std::string, obj.get_base(), obj.set_base(val))
(int, int, obj.get_age(), obj.set_age(val))
)
Well, it looks (by experimentation) that one can put all sorts of valid expressions in BOOST_FUSION_ADAPT_ADT
. I am not very sure if this is optimal (for example if fusion will make copies when accessing the elements), so other answers are welcomed.
#include <boost/fusion/adapted/adt/adapt_adt.hpp>
BOOST_FUSION_ADAPT_ADT(
employee2,
(static_cast<std::string const&>(obj), obj.std::string::operator=(val))
(obj.age, obj.age = val)
)
int main(){
employee2 e2;
boost::fusion::at_c<0>(e2) = "Pepe";
boost::fusion::at_c<1>(e2) = 37;
cout << e2 << " " << e2.age <<'\n';
}
This may prevent some copies and seems to work in more cases (e.g. boost::fusion::copy
) but I am not sure why:
BOOST_FUSION_ADAPT_ADT(
employee2,
(std::string, std::string const&, obj, obj.std::string::operator=(val))
(int, int const&, obj.age, obj.age = val)
)