what is the output of conditional operator with unary operator

I have the following code where behavior is not clear to me. Can some one please help how conditional operator evaluate the following code and output ans as 1

#include

int main() {

bool delayMessages=0;
bool Delay = false;
delayMessages += Delay ? 1 : -1;
std::cout << "Hello world!"<<delayMessages;

return 0;
} 

Ans: Hello world!1

Can soemone please help how thsi code is evaluated "delayMessages += Delay ? 1 : -1;"

>Solution :

The expression on the right hand side is evaluated like an if-statement.

if (Delay == true)
   return 1;
else
   return -1;

The result is then used for the += assignment.

Since Delay == false, the return value of the ternary operator is -1. The fact that you’re operating on a boolean instead of an int can make it look like you got the +1 back.

Note that you get a compiler warning C4804:

warning C4804: ‘+=’: unsafe use of type ‘bool’ in operation