C++ const 与 指针

#include using namespace std;int main(){    int a1 = 13;    int a2 = 19;    int const p1 = 0;    const int p2 = 0;   // p1 和 p2 完全一样/* error: invalid conversion from 'const int *' to 'int *'   '&p1' is 'const int *'   'p3' is 'int *'   此处声明的p3是int*的const,自身不可变,而指向的数据可变,   然而,现在指向的p1是const,不可变,所以编译器报错*/ //  int * const p3 = &p1;    int * const p3 = &a1; // ok//  p3 = &a2; //p3 不可变, error: assignment of read-only variable 'p3'    (*p3)++; // ok! equal a1++;    int const * p4 = &p1;    p4 = &a2; // ok!//  (*p4)++; //p4 指向的数据不可变, error: increment of read-only location '* p4'    const int * p5 = &p2; // p4 和 p5 完全一样    p5 = &a2;//  (*p5)++;    const int * const p6 = &a1; // ok!//  p6 = &a2; // error: assignment of read-only variable 'p6'//  (*p6)++; // error: increment of read-only location '*(const int*)p6'    const int * const p7 = &p1; // ok!//  p7 = &a2; // 同p6//  (*p7)++;  // 同p6    cout << "p3 = " << p3 << ", *p3 = " << *p3 << endl;    cout << "p4 = " << p4 << ", *p4 = " << *p4 << endl;    cout << "p5 = " << p5 << ", *p5 = " << *p5 << endl;    cout << "p6 = " << p6 << ", *p6 = " << *p6 << endl;    cout << "p7 = " << p7 << ", *p7 = " << *p7 << endl;    return 0;}

运行结果: