Overloading operator < in C++

Question

it seems that overloading operators is not working for me, I am probably doing something wrong.

I've got this structure

typedef void (*fptr)(void);
struct Mystruct
{
    int id;
    int priority;
    double timeSaved;
    double aktivationTime;
    fptr eventPointer;
    MystructnextPtr;

    Mystruct(int id, int priority, double timeSaved, double aktivationTime, fptr eventPointer);
};

This operator:

bool operator <(const Mystruct& x, const Mystruct& y)
{
    return std::tie(x.aktivationTime, x.priority, x.timeSaved) < std::tie(y.aktivationTime, y.priority, y.timeSaved);
}

And am trying to execute this code:

Mystruct* struct1 = new Mystruct(5, 10, 0, 15.3, f1);
Mystruct* struct2 = new Mystruct(5, 10, 0, 14.3, fi);

if (struct1 < struct2)
{
    cout << "struct1 is smaller!" << endl;
}
else
{
    cout << "struct2 is smaller!" << endl;
}

It ALWAYS says to me that struct1 is smaller, regardless of what is in those structures. What am doing wrong?

You're comparing the pointers and not the structs. Try if (*struct1 < *struct2 )... — Tony Lee, Nov 25 '14 at 23:17
@TonyLee it says, that I don't have the back operator created. — Dracke, Nov 25 '14 at 23:21
post the code that yielded that or it didn't happen :-p... "I tried xyz and it yielded abc..." — UpAndAdam, Nov 25 '14 at 23:27
@Dracke: "so how should I create the structures?" `Mystruct struct1(5, 10, 0, 15.3, f1);` is the conventional way. Save `new` for when you really need it. — Mike Seymour, Nov 26 '14 at 00:05

score 0 · Accepted Answer · edited May 23 '17 at 12:20

0

You created an operator handling constant references to Mystruct. (const Mystruct&). However you are using the comparator operator on non-const pointers to non-const MyStruct instances.

You have one real option:
- deference your pointers (*struct1 < *struct2)

However also take a look here.. C++: Operator overloading of < for pointers to objects

edited May 23 '17 at 12:20

Community

1
1

answered Nov 25 '14 at 23:25

UpAndAdam

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Option 1 is not viable. At least one operand must be a user-defined type. – chris Nov 25 '14 at 23:27
you are correct amending answer.. always forget about that. – UpAndAdam Nov 25 '14 at 23:30

Overloading operator < in C++

1 Answers1