Meaning of *(volatile unsigned int *) 0x00 = 0x00;

Question

What is the meaning of the following line of code?

*(volatile unsigned int *) 0x00 = 0x00;

It is used in Assert definition:

void Assert()
{
    // (some other code above)

    *(volatile unsigned int *) 0x00 = 0x00;

    return;
}

Answer 1

I can guess it is trying to cause the program to crash with a segmentation fault or something similar.

Whoever wrote the code was thinking "I hope the compiler does not optimize this crash away, so let's put a volatile in front of the pointer dereference".

But all the code is doing is causing undefined behavior that is not guaranteed to crash.

An std::terminate() is a much better option if you want your program to terminate then that UB Assert()

Also note that an assert should be given a condition, and then if the condition is false the assert should trigger some failure code. Ot is not meant to be an "exit this program" function. See linked comment

Answer 2

Cast 0x00 to pointer to volatile unsigned int and then dereference it with operator * and write to that address 0x00. Which is undefined behavior and on most systems will cause crash.