No match for operator when using with a function

Question

I have overloaded the following greater than operator: ``` bool operator > (Person & a, Person & b) { //firstname is a string data type return (a.FirstName > b.FirstName); } ``` Which works fine if I have something like the following: ``` Person a = myPersonA; Person b = myPersonB; return myPersonA > myPersonB; ``` However, within my `Person` class I have defined a `Person getByID(int id)` function, which returns an instance of a Person, by the given ID. If I try to use my operator with the returned values from this function like this: ``` bool whosGreater = listPeople.getById(1) > listPeople.getById(2); ``` I get `"Error: no match for operator >(Person&, Person&)"` but if I do the following it works fine: ``` Person a = listPeople.getById(1); Person b = listPeople.getById(2); bool whosGreater = a > b; ``` Is there something I am not seeing here? It seems to me it should work. PS: This is for a homework, so I could really get away with declaring the variables and assign them what the…

Accepted Answer

The returned value from a function is a temporary value, not a "normal" Person object. Temporary values can only be passed in as const parameter references, so changing your parameters to `const` references should work well;

```
bool operator > (const Person & a, const Person & b)
{
   //firstname is a string data type
   return (a.FirstName > b.FirstName);      
}
```

No match for operator > when using with a function

Solution

Problem