[C++知识库]C++ 函数重载

C++ 函数重载 （参数分别为基类 派生类类型）

#include <iostream>

 #include <typeinfo>
 #include <cxxabi.h>

std::string getClearName(const char* name)
{
    int status = -1;
    char* clear_name = abi::__cxa_demangle(name, NULL, NULL, &status);
    const char* demangle_name = (status==0) ? clear_name : name;
    std::string ret_val(demangle_name);
    free(clear_name);
    return ret_val;
}


class A{
    public:
    int value;
    A(int x):value(x){};
};
class B:public A{
    public:
    int base;
    B(int x, int y):A(x),base(y){};
};
void print(A a){
    std::cout << getClearName(typeid(a).name()) << std::endl;
    std::cout << a.value << std::endl;
}
void print(B b){
    std::cout << getClearName(typeid(b).name()) << std::endl;
    std::cout << b.value << " " << b.base << std::endl;
}
int main(){
    A a(1);
    B b(1,2);
    print(a);
    print(b);
    return 0;
}

# g++ Overload.cpp -o Overload
# ./Overload
A
1
B
1 2

如果去掉派生类函数

void print(B b){
    std::cout << getClearName(typeid(b).name()) << std::endl;
    std::cout << b.value << " " << b.base << std::endl;
}

那么

# g++ OverloadOne.cpp -o OverloadOne
# ./OverloadOne
A
1
A
1