What are some examples of using std::optional in C++?

Can you give me some examples of using std::optional in C++?

Sure! std::optional is used to represent optional values. For example, you can use it to indicate that a function might not return a value.

Can you show me a code example?

Absolutely! Here's a simple example:

#include <iostream>
#include <optional>

std::optional<int> findValue(int key) {
    if (key == 42) return 100;
    return std::nullopt;
}

int main() {
    auto result = findValue(42);
    if (result) {
        std::cout << "Value found: " << *result << std::endl;
    } else {
        std::cout << "Value not found" << std::endl;
    }
}

This function returns an optional integer.

What happens if I try to access the value without checking?

If you try to access the value without checking, it can lead to undefined behavior. Always check if the optional has a value before dereferencing it!

Are there any performance considerations with std::optional?

Yes, std::optional can have some overhead compared to using raw pointers or references, but it provides safety and clarity in your code.