Making a vector of linked lists?

How can I make a vector of linked lists?

For example I have a struct of properties (for the linked-list) defined as follows:

typedef struct property {
    string info;
    property* implication;
} property;

And then I have a class object:

class objects {
private:
    vector<property> *traits;
public:
    void giveProperty(property *x) {
    traits.push_back(&x);
    }
};

Where what I want to do conceptually is give an object certain properties, and each property has a series of implications (which is the linked list) which I can use later. But I am getting the error:

request for member 'push_back' in '((objects*)this)->objects::traits', which is of non-class type 'std::vector >*'

I am hav开发者_开发技巧ing trouble getting this to work. Sorry if this is unclear, if you have questions I will try clarifying myself.

in class objects, you have declared a pointer to a vector of properties, when really you want a vector of property pointers:

class objects {
private:
    vector<property*> traits;    // Note where * is
public:
    void giveProperty(property *x) {
        traits.push_back(x);    // Note that x is already a pointer, no need to take its address
    }
};

I'm not sure why you are using raw pointers. You say you want to have a linked list, but you don't implement that anywhere. Why not use the std::list container for your linked lists and lose the pointers altogether?

#include <string>
#include <vector>
#include <list>

using std::string;
using std::vector;
using std::list;

struct implication {
    implication(string name) : name(name) {}
    string name;
};

struct property {
    property(string info) : info(info) {}
    string info;
    list<implication> implList;
};

class object {
private:
    vector<property> traits;
public:
    void giveProperty(const property& x) {
        traits.push_back(x);
    }
};

int f() {
    object o;
    property p1("p1");
    property p2("p2");
    implication i("implic");

    p1.implList.push_back(i);
    p1.implList.push_back(implication("other implic"));

    o.giveProperty(p1);

    o.giveProperty(property("p3"));
}

Change this

traits.push_back(&x);

to this:

traits->push_back(*x);

Or probably/possibly, you would want to change this:

vector<property> *traits;

to this:

vector<property*> traits;

I would go for the latter one!

Do you understand what pointers are?

vector<property*> *traits; 

You're creating a pointer to a vector, not a vector. You would need to create one:

traits = new vector<property*>;

then access it as:

traits->push_back(x);

Change -

vector<property> *traits;

to

vector<property*>  traits; // Needs to be the declaration.

Since you are trying to push_back addresses to the vector traits.

void giveProperty(property *x) {
    traits.push_back(&x);
                     ^ Error : With the above modifications made, traits can hold
                       elements of type property*. By doing &x, you are trying to do
                       push_back pointer's address which in that case vector should
                       hold elements of type property**. So, just remove the & 
                       symbol before x while push_back because x is already of type
                       property*

}