that is bug?

[Ali Çehreli]

On 04/07/2018 10:53 AM, Ali wrote:
 > On Saturday, 7 April 2018 at 15:26:56 UTC, Ali Çehreli wrote:
 >> On 04/07/2018 02:07 AM, sdvcn wrote:
 >>>      string stt = "none";
 >>>      true?writeln("AA"):writeln("BB");   ///Out:AA
 >>>          true?stt="AA":stt="BB";    <<<<-----///Out:BB
 >>>      writeln(stt);
 >>
 >> It is a bug because the behavior does not match the spec:
 >>
 >>   https://issues.dlang.org/show_bug.cgi?id=18743
 >>
 >> Ali
 >
 > Hi Ali C
 >
 > I think it also a bug because the ternary seem to be returning the
 > second part

Maybe... but the following is not a good test for that because the 
return value of the assignment operator would always be stt regardless 
of which expression is evaluated.

 >
 > try
 >
 >      string stt = "none";
 >      string b = "";
 >      true?writeln("AA"):writeln("BB");   ///Out:AA
 >      b = (true ? stt="AA":stt="BB");    ///Out:BB
 >      writeln(stt);
 >      writeln(b); ///Out:BB

I tried something else and noticed that it doesn't actually evaluate the 
third expression because b is never changed:

import std.stdio;

void main() {
     int a;
     int b;
     int * c = &(true ? a = 1 : b = 2);
     writefln("a:%s %s", a, &a);
     writefln("b:%s %s", b, &b);
     writefln("c:  %s", c);
}

Output:

a:2 7FFDBBF57DB0  <-- Got the value of the third expression (BAD)
b:0 7FFDBBF57DB4  <-- Not changed (good)
c:  7FFDBBF57DB0  <-- Address of a (good)

So, the expression correctly decides to affect and returns 'a' but uses 
the wrong value to assign.

Ali