memb_ptr.cpp

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C++ 代码 · 共 107 行

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// example of member pointer use across virtual inheritance
// only WATCOM and Borland can execute this program correctly
#include <iostream.h>

struct V1 {
    int get() { return v; }
    void set( int x ) { v = x; }
private:
    int v;
};
struct V2 {
    int get() { return v; }
    void set( int x ) { v = x; }
private:
    int v;
};
struct XX : virtual V1, virtual V2 {
};
struct YY : virtual V2, virtual V1 {
};
struct ZZ : XX, YY {
};

unsigned errors;

ZZ data;

void test_XX( XX *p, int (XX::*mp)( void ), int should_be )
{
    int member_value;

    member_value = (p->*mp)();
    if( member_value != should_be ) {
        ++errors;
    }
    cout << "(" << member_value << ") should be " << should_be << endl;
}

void test_YY( YY *p, int (YY::*mp)( void ), int should_be )
{
    int member_value;

    member_value = (p->*mp)();
    if( member_value != should_be ) {
        ++errors;
    }
    cout << "(" << member_value << ") should be " << should_be << endl;
}

void test_ZZ( ZZ *p, int (ZZ::*mp)( void ), int should_be )
{
    int member_value;

    member_value = (p->*mp)();
    if( member_value != should_be ) {
        ++errors;
    }
    cout << "(" << member_value << ") should be " << should_be << endl;
}

void main()
{
    data.V1::set(-1);
    data.V2::set(-2);
    test_XX( &data, &V1::get, -1 );
    test_XX( &data, &V2::get, -2 );
    test_YY( &data, &V1::get, -1 );
    test_YY( &data, &V2::get, -2 );
    test_ZZ( &data, &V1::get, -1 );
    test_ZZ( &data, &V2::get, -2 );
    if( errors != 0 ) {
        cout << "FAILURE" << endl;
    }
}