Re: Problem understanding 'boost::intrusive::list_member_hook<>'

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2021-09-07 15:33:22

> 
> But when I try that here, VS2019 throws up this compiler error:-
> 
>  Â Â Â  error C2039: 'default_list_hook': is not a member of 'animal'
> 
> Can anyone explain what I'm doing wrong??
> 
> John

It's difficult to see what's wrong without a full compilable example but 
the following snippet works perfectly for me in Visual 2019:

#include <boost/intrusive/list.hpp>
#include <string>
#include <iostream>

using namespace std;

class animal
{
    public:
       animal (string n, int l) : name{move(n)}, legs{l} {}

       string name;
       int legs;
       boost::intrusive::list_member_hook<> _animal_hook;
};

typedef boost::intrusive::member_hook<animal,
    boost::intrusive::list_member_hook<>, &animal::_animal_hook>
       AnimalHookOption;

typedef boost::intrusive::list<animal, AnimalHookOption> Animals;

void print_list (const Animals& elem)
{
    for (const Animals::value_type& a : elem)
       cout << "A " << a.name << " has " << a.legs << " legs" << '\n';
}

int main()
{
    animal a1{"dog", 4};
    animal a2{"spider", 6};
    animal a3{"budgie", 2};
    Animals animals;

    animals.push_back(a1);
    animals.push_back(a2);
    animals.push_back(a3);
    print_list (animals);

    return 0;
}