所以我在我的程序中检查事实时遇到问题继承人代码: 该向量包含3种类型的派生对象我只是想要向量中的每个基础对象的子项。我似乎无法找到适当的语法。STLs std :: map和std :: vector;检查地图中的对象类型
class Base{
virtual void method() = 0;
}
class derived_1 : public Base{
virtual void method();
}
class derived_2 : public Base{
virtual void method();
}
class derived_3 : public Base{
virtual void method();
}
class general_class{
private:
//objects of derived types have been instantiated into the vector already
map<string,vector<Base*>> base_map;
void print(){
//This line prints the key and size
cout << iter->first << " " << iter->.size();
int d1_count = 0, d2_count = 0,d3_count = 0;
for(iter=accounts_map.begin();iter !=accounts_map.end();iter++){
//So I know that the loop iterates through the map
//how do I fact check to determine which object was found?
//The below code is incorrect
if(iter->second[i] == (derived_1 /*"objects"*/)){
d1_count++;
}
if(iter->second[i] == (derived_2 /*"objects"*/)){
d2_count++;
}
if(iter->second[i] == (derived_3 /*"objects"*/)){
d3_count++;
}
}
}
}
我不确定语法是什么或检查正确的对象类型背后的逻辑。
使用dynamic_cast。 derived_1 * d1; d1 = dynamic_cast(iter-> second [i]); if(d1)d1_count ++; –
user1438832
顺便说一句,你需要另一个循环。第一个循环遍历'map'的项目。需要另一个循环来遍历'vector'的项目。 –
是的,我刚刚意识到我需要另一个循环的载体。通过矢量的语法是什么? –