Re: [Challenge] implementing the ambiguous operator in D

[Denis Koroskin]

On Sun, 05 Sep 2010 19:17:55 +0400, bearophile <bearophileh...@lycos.com>  
wrote:

Denis Koroskin:
The code above should print:
state saved
state restored
(not tested)

On Windows, dmd 2.048, this code:


import std.c.stdio: puts;

version (Windows) {
    alias int[16] jmp_buf;
    extern (C) extern {
        int setjmp(ref jmp_buf env);
        void longjmp(ref jmp_buf env, int value);
    }
}

struct State {
     int save() {
         return setjmp(buf);
     }

     void restore(int status) {
         assert(status != 0);
         longjmp(buf, status);
     }

     private jmp_buf buf;
}

void main() {
     State state;
     int result = state.save();
     if (result == 0) {
         // first time here
         puts("state saved");
         state.restore(1);
     } else {
         assert(result == 1);
         puts("state restored");
     }
}


Gives an Access Violation after printing state saved.

Bye,
bearophile

Turn main into an "extern(C) int main()" and it works.
Surround the code with try/catch block and it fails again.

Looks like longjmp fails if you run the function inside a try/catch block  
for some reason.