Re: Operater < overloading for struct problem
Frank wrote:
I am having trouble overloading the < operator for an assignment. I
use a struct that contains information and I would like to sort this
structure using STL sort with my own criteria of sorting. Basically, I
would like to sort on visitor count of the Attraction structure.
However, it never uses the < overloaded operator with my code.
Handler.h:
#ifndef H_HANDLER //Guard
#define H_HANDLER
#include <iostream>
#include <vector>
using namespace std;
struct Attraction {
string name;
int visitors;
};
class Handler { //Define the class Handler
private:
vector<Attraction*> attractions ;
vector<Attraction*>::iterator p ;
public: //Public functions
~Handler();
void addAttraction(string name, int visitors);
void printAttractions();
};
#endif
and in the Handler.cpp I have:
Handler.cpp - snippet:
bool operator<(const Attraction& a,const Attraction& b){
return a.visitors < b.visitors;
}
Here is the function that performs the sort after adding a value:
void Handler::addAttraction(string name, int visitors){
Attraction *attr;
attr=new Attraction();
attr->name=name;
attr->visitors=visitors;
attractions.push_back(attr);
sort(attractions.begin(),attractions.end());
}
However, whatever I do, it will never use the overloaded < operator
for sorting. What am I doing wrong?
Your operator< is defined for _objects_, but your vector is storing
_pointers_. Drop the 'new', drop the pointers, keep objects, and
everything will be fine.
You can declare/define a local Attraction object in 'addAttraction'
and then push_back it, the vector will make a copy.
[..]
V
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