//通过差错码可以对异常很好的处理
#include<iostream> #include<system_error> #include<future> #include<exception> #include<string> template<typename T> void processCodeException(const T& e) { using namespace std; auto c = e.code(); cerr << "-category: " << c.category().name() << endl; cerr << "-value: " << c.value() << endl; cerr << "-msg: " << c.message() << endl; cerr << "-def category: " << c.default_error_condition().category().name() << endl; cerr << "-def value: " << c.default_error_condition().value() << endl; cerr << "-def name " << c.default_error_condition().message() << endl; } void processException() { using namespace std; try { throw; } catch (const ios_base::failure& e) { cerr << "I/O EXCEPTION: " << e.what() << endl; processCodeException(e); } catch (const system_error& e) { cerr << "SYSTEM EXCEPTION: " << e.what() << endl; processCodeException(e); } catch (const future_error& e) { cerr << "FUTURE EXCEPTION: " << e.what() << endl; processCodeException(e); } catch (const bad_alloc& e) { cerr << "BAD_ALLOC EXCEPTION: " << e.what() << endl; //processCodeException(e); } catch (const exception& e) { cerr << "EXCEPTION: " << e.what() << endl; } catch (...) { cerr << "EXCEPTION(unknown)" << endl; } } int main() { try { //手动抛出异常 //error_code(int _Val, const error_category& _Cat) _NOEXCEPT //error_code的一个构造函数_Val是枚举值表示错误的种类 //因为error_category是抽象类不能构造对象,因此通过函数返回 std::system_error e(std::error_code(5,std::system_category())); throw e; } catch (...) { processException(); } system("pause"); return 0; }