c++继承不知道哪里错了编译不通过

Question

#include
using namespace std;

class CP_A
{
public:
int m_a;
CP_A(): m_a(10) {cout << "A(" << m_a << ")" << endl;}
CP_A(int i): m_a(i) {cout << "a[" << m_a << "]" << endl;}
};

class CP_B : public CP_A
{
public:
int m_b;
CP_B():CP_B(20) {cout << "B(" << m_b << ")" << endl;}
CP_B(int i):m_b(i),CP_A(i){cout << "b[" << m_b << "]" << endl;}
};

int main()
{
CP_B b;
cout << "m_a=" << b.m_a << endl;
cout << "m_b=" << b.m_b << endl;
return 0;
}

Answer 1

CP_B():CP_B(20) {cout << "B(" << m_b << ")" << endl;}

这一行你是想写m_b(20)吧？