Base *bp;
Derived *dp;
// compare type
at run time of two objects
if (typeid(*bp) == typeid(*dp))
{
// bp and
dp point to objects of the same type
}
// test whether run time type
is a specific type
if (typeid(*bp) ==
typeid(Derived)) {
// bp
actually points to a Derived
}
注意，typeid 的操作數是表示對象的表達式——測試
*bp，而不是 bp：
Base *bp = new
Derived ;
cout<<typeid(bp)<<endl;
//輸出 Class Base *
cout<<typeid(*bp)<<endl;
//輸出 Class Derived