The C++ –> is used for … well. I came across this post on Stackoverflow where someone asks what the –> operator in C++ is for, with the following code snippet:

while (x --> 0)
{
    printf("%d ", x);
}

I asked ChatGPT what the –> operator is, and it correctly stated that it “appears to use a non-standard and unconventional usage of the --> operator, which is not a standard operator in C++.” – which is quite good considering the hallucination it often shows. Furthermore, it says:

In C++, the --> operator doesn’t have any predefined meaning or behavior. Instead, it appears that the code you’ve shown is trying to use the -- (decrement) operator followed by the > (greater than) operator. However, this is not valid C++ syntax.

This is pretty much in line with the answer of the post on Stack Overflow.

Just for the fun, I asked ChatGPT how an implementation would look like if it was a valid operator, and this is what it came up with:

#include <iostream>

class CustomClass {
private:
    int value;

public:
    CustomClass(int val) : value(val) {}

    // Overloading the -->(...) operator
    CustomClass operator-->(int incrementValue) {
        CustomClass temp(*this);
        value += incrementValue;
        return temp;
    }

    int getValue() const {
        return value;
    }
};

int main() {
    CustomClass obj(5);

    // Using the custom -->(...) operator
    obj = obj-->(3);

    std::cout << "Value after custom operation: " << obj.getValue() << std::endl;

    return 0;
}

Now I asked it if it could imagine what the –> operator could be used for. Here is the answer:

Let’s imagine a use case for the --> operator in a hypothetical scenario:

Suppose you are working on a complex numerical simulation or mathematical modeling library in C++. In such a library, you might frequently work with mathematical expressions and matrices. You could use the --> operator as a custom operator for matrix operations, specifically for updating matrix elements in a concise and intuitive way.

It also mentions I should keep in mind that this is entirely speculative, as the --> operator doesn’t exist in the C++ language, and inventing custom operators should be done judiciously and with care for code readability and maintainability.

Then it produced some code:

#include <iostream>
#include <vector>

class Matrix {
private:
    std::vector<std::vector<double>> data;

public:
    Matrix(const std::vector<std::vector<double>>& input) : data(input) {}

    // Overload the --> operator for element updates
    double& operator-->(const std::pair<int, int>& indices) {
        int row = indices.first;
        int col = indices.second;

        if (row >= 0 && row < data.size() && col >= 0 && col < data[0].size()) {
            return data[row][col];
        } else {
            throw std::out_of_range("Matrix element out of bounds");
        }
    }

    // Display matrix
    void display() const {
        for (const auto& row : data) {
            for (const double& value : row) {
                std::cout << value << ' ';
            }
            std::cout << '\n';
        }
    }
};

int main() {
    std::vector<std::vector<double>> initialData = {{1.0, 2.0}, {3.0, 4.0}};
    Matrix mat(initialData);

    // Use the custom --> operator to update matrix elements
    mat --> std::make_pair(0, 1) = 5.0;

    // Display the updated matrix
    mat.display();

    return 0;
}

• The --> operator is overloaded for the Matrix class to update individual elements of the matrix.
• The operator takes a pair of indices (row and column) and returns a reference to the corresponding matrix element.
• It performs bounds checking to ensure that the indices are within the matrix dimensions.

Well, if C++ had a --> operator, we’d probably have debates about whether it should be called the “rocket ship operator” or the “arrow arrow operator.” And we’d have t-shirts with clever slogans like “I put the ‘fun’ in ‘function'” for C++ developers who love their custom operators. But for now, let’s stick with the good ol’ . and -> and leave the hypothetical operators to our wildest coding dreams! 😄