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C++的异常类(exception classes) 详解2014-11-20异常类(exception classes)包含4种基类,bad_cast, bad_alloc,runtime_error, logic_error;

runtime_error: 错误只有当程序运行时, 才能检测出来;

logic_error: 应用程序检测出的逻辑错误.

其中bad_cast, bad_alloc使用默认构造器, runtime_error, logic_error, 必须使用string(C-style或stl)进行初始化;

用户定义的类也可以继承(inherit)自异常类, 并初始化相应的参数;

代码如下:

/** cppprimer.cpp**Created on: 2013.11.28*Author: Caroline*//*eclipse cdt, gcc 4.8.1*//* setlocale example */#include <iostream>#include <string>#include <stdexcept>using namespace std;class out_of_stock : public std::runtime_error{public://初始化基类的runtime_errorexplicit out_of_stock(const std::string &s) : std::runtime_error(s) {}};class id_mismatch : public std::logic_error{public:explicit id_mismatch(const std::string &s) : std::logic_error(s) {}id_mismatch(const std::string &s, const std::string &lhs, const std::string &rhs) :std::logic_error(s), left(lhs), right(rhs) {}const std::string left, right;};struct My_food{My_food(const std::string fi, const int fn) : food_id(fi), food_num(fn) {}My_food& operator+=(const My_food& rhs);std::string food_id;int food_num;};My_food& My_food::operator+=(const My_food& rhs){if(this->food_id != rhs.food_id)throw id_mismatch("wrong id", this->food_id, rhs.food_id);this->food_num += rhs.food_num;return *this;}int main (void){My_food M1("Apple", 3), M2("Pear", 2), M3("Apple", 2);try{M1 += M3;std::cout << M1.food_id << ":" << M1.food_num << std::endl;M1 += M2;}catch(const id_mismatch &e){std::cerr << e.what() << ": left id("<< e.left <<") right id(" << e.right << ")" << std::endl;}}
输出:

Apple:5wrong id: left id(Apple) right id(Pear)
作者:csdn博客 Spike_King