modern-cpp

# 现代 C++20/23 特性 ## 概念与约束 (Concepts) cpp #include // 定义自定义概念 template concept Numeric = std::integral || std::floating_point; template concept Hashable = requires(T a) { { std::hash{}(a) } -> std::convertible_to; }; template concept Container = requires(T c) { typename T::value_type; typename T::iterator; { c.begin() } -> std::same_as; { c.end() } -> std::same_as; { c.size() } -> std::convertible_to; }; // 使用概念进行函数约束 template T add(T a, T b) { return a + b; } // 基于概念的重载 template void process(T value) { std::cout << "处理整数: " << value << 'n'; } template void process(T value) { std::cout << "处理浮点数: " << value << 'n'; } ## 范围库 (Ranges) 与视图 (Views) cpp #include #include #include // 基于范围的算法 std::vector numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; // 过滤、转换、获取 - 均为惰性求值 auto result = numbers | std::views::filter([](int n) { return n % 2 == 0; }) | std::views::transform([](int n) { return n * n; }) | std::views::take(3); // 仅在需要时复制到 vector std::vector materialized(result.begin(), result.end()); // 自定义范围适配器 auto is_even = [](int n) { return n % 2 == 0; }; auto square = [](int n) { return n * n; }; auto pipeline = std::views::filter(is_even) | std::views::transform(square); auto processed = numbers | pipeline; ## 协程 (Coroutines) cpp #include #include #include // 生成器协程 template struct Generator { struct promise_type { T current_value; auto get_return_object() { return Generator{std::coroutine_handle::from_promise(*this)}; } std::suspend_always initial_suspend() { return {}; } std::suspend_always final_suspend() noexcept { return {}; } std::suspend_always yield_value(T value) { current_value = value; return {}; } void return_void() {} void unhandled_exception() { std::terminate(); } }; std::coroutine_handle handle; Generator(std::coroutine_handle h) : handle(h) {} ~Generat