example4_optional_as_class_member.cpp

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#include <iostream>
#include <optional>
#include <string>

class User {
public:
    User(const std::string& name) : name_(name) {}
    void set_email(const std::string& email) { email_ = email; }
    std::string get_email() const { return email_.value_or("No email set"); }

private:
    std::string name_;
    std::optional<std::string> email_;
};

int main() {
    User user("Alice");
    std::cout << "Email: " << user.get_email() << std::endl;
    
    user.set_email("alice@example.com");
    std::cout << "Email: " << user.get_email() << std::endl;
    
    return 0;
}