Modern features for clearer code | C++

Modern C++ has features that help express intent. They are useful when they make code clearer, safer, or less error-prone.

nullptr

Use nullptr for null pointers:

Widget* selected{nullptr};

It has a pointer-specific type and avoids old 0 and NULL confusion.

enum class creates scoped named choices:

enum class Mode {
    read,
    write,
};

Values do not leak into the surrounding scope and do not casually convert to integers.

Structured bindings unpack pair-like or aggregate values:

for (const auto& [name, score] : scores) {
    std::cout << name << ": " << score << "\n";
}

They are especially useful with maps and simple structs.

constexpr says a value or function can be evaluated at compile time when its inputs allow it:

constexpr int max_users{100};

constexpr int square(int value) {
    return value * value;
}

Use it for constants and simple computations that should be available during compilation.

std::optional<T> represents “maybe a value”:

std::optional<User> find_user(int id);

if (auto user = find_user(42)) {
    std::cout << user->name << "\n";
}

This is clearer than returning a sentinel value such as -1 when no value exists.

std::variant represents one of several known types:

using Setting = std::variant<int, bool, std::string>;

It is useful when a value has a closed set of possible shapes. Keep early uses simple.

std::string_view is a non-owning view of text:

void log(std::string_view message);

It does not own characters. Do not store a string_view unless you are certain the referenced text outlives it.

Next, you will design error handling strategies.