C++命名空间与模块化

C命名空间与模块化命名空间是C组织代码、避免名称冲突的机制。合理使用命名空间可以提高代码的可维护性和模块化程度。命名空间基本用法使用namespace关键字定义。#include#include#includenamespace math {int add(int a, int b) { return a b; }int multiply(int a, int b) { return a * b; }namespace advanced {double power(double base, int exp) {double result 1.0;for (int i 0; i exp; i) result * base;return result;}double sqrt(double x) {double guess x / 2.0;for (int i 0; i 10; i) {guess (guess x / guess) / 2.0;}return guess;}}}void namespace_basics() {std::cout 10 20 math::add(10, 20) \n;std::cout 5 * 6 math::multiply(5, 6) \n;std::cout 2^10 math::advanced::power(2.0, 10) \n;std::cout sqrt(2) math::advanced::sqrt(2.0) \n;}using声明引入特定名称。void using_declaration() {using math::add;using math::advanced::power;std::cout add: add(100, 200) \n;std::cout power: power(3.0, 4) \n;}using指令引入整个命名空间。namespace graphics {void render() { std::cout Graphics render\n; }}namespace audio {void render() { std::cout Audio render\n; }}void using_directive() {using namespace graphics;render();audio::render();}命名空间别名简化长命名空间。namespace company_project_module {class Widget {public:void process() { std::cout Process widget\n; }};}void alias_demo() {namespace cpm company_project_module;cpm::Widget w;w.process();}匿名命名空间实现内部链接。namespace {int internal_counter 0;void internal_function() {internal_counter;std::cout Internal count: internal_counter \n;}}void anonymous_demo() {internal_function();internal_function();}内联命名空间用于版本管理。namespace library {inline namespace v2 {class API {public:void execute() { std::cout v2 API\n; }};}namespace v1 {class API {public:void execute() { std::cout v1 API\n; }};}}void inline_namespace_demo() {library::API api;api.execute();library::v1::API old_api;old_api.execute();}命名空间可以分散定义。namespace data {struct User {std::string name;int age;};}namespace data {struct Product {std::string name;double price;};}void distributed_namespace() {data::User u{Alice, 30};data::Product p{Widget, 9.99};std::cout u.name bought p.name \n;}ADL参数依赖查找允许不带命名空间调用函数。namespace util {struct Point { int x, y; };void print(const Point p) {std::cout ( p.x , p.y )\n;}}void adl_demo() {util::Point p{10, 20};print(p);}命名空间别名在函数内部更安全。void safe_alias() {namespace m math::advanced;std::cout m::sqrt(16.0) \n;}命名空间是C代码组织的基础合理使用可以提高代码的可维护性和可读性。