类型转换演示视频 https://www.bilibili.com/video/av82226338/
对应的代码：
1 #include <iostream> 2 3 int main() { 4 int i = 42; 5 std::cout << i << std::endl; // prints 42 6 if (i) // condition will evaluate as true 7 i = 0; 8 std::cout << i << std::endl; // prints 0 9 10 11 bool b = 42; // b is true 12 std::cout << b << std::endl; // prints 1 13 14 int j = b; // j has value 1 15 std::cout << j << std::endl; // prints 1 16 17 double pi = 3.14; // pi has value 3.14 18 std::cout << pi << std::endl; // prints 3.14 19 20 j = pi; // j has value 3 21 std::cout << j << std::endl; // prints 3 22 23 unsigned char c = -1; // assuming 8-bit chars, c has value 255 24 i = c; // the character with value 255 is an unprintable character 25 // assigns value of c (i.e., 255) to an int 26 std::cout << i << std::endl; // prints 255 27 28 return 0; 29 }