Best practices for returning optional results in C++17:
std::optional<User> FindUser(int id);
auto user = FindUser(42);
// 1. Safe default fallback with value_or
std::string name = user ? user->name : "Guest";
// 2. Monadic operations in C++23 (and_then, transform, or_else)
auto email = FindUser(42)
.transform([](const User& u) { return u.email; })
.value_or("no-email@domain.com");Avoid calling .value() directly without checking .has_value() first to prevent std::bad_optional_access exceptions in production services.