C++ 异常小记

catch必定使用拷贝构造函数

如下代码编译不通过，因为拷贝构造被标记delete

#include <stdexcept>
#include <cstdlib>
#include <iostream>

using namespace std;

class sonExc : public exception {
public:
    sonExc ( const char* const msg ) : exception ( msg ) {

    }
    sonExc ( const sonExc & e ) = delete;
};

int main()
{
    try {
        sonExc e { "Hello" };
        throw e;
    }
    catch ( sonExc &e ) {
        cout << "sonExc:" << e.what() << endl;
    }
    catch ( exception &e ) {
        cout << "exception:" << e.what() << endl;
    }

    system ( "pause" );
}

throw 指针

依照优先匹配原则

可以匹配 基类指针、本类指针和void*，哪个在前面优先哪个

#include <stdexcept>
#include <cstdlib>
#include <iostream>

using namespace std;

class sonExc : public exception {
public:
    sonExc ( const char* const msg ) : exception ( msg ) {

    }
    sonExc ( const sonExc & e ) = delete;
};

int main()
{
    try {
        sonExc *e = new sonExc{ "Hello" };
        throw e;
    }
    catch ( int e ) {
        cout << "int *" << ( e ) << endl;
    }
    catch ( void* e ) {
        cout << "void *" << reinterpret_cast<int> ( e ) << endl;
    }
    catch ( sonExc *e ) {
        cout << "sonExc:" << e->what() << endl;
    }
    catch ( exception *e ) {
        cout << "exception:" << e->what() << endl;
    }

    system ( "pause" );
}