dmd-2.067.0-b1

[Dennis Ritchie via Digitalmars-d-learn]

On Friday, 13 February 2015 at 13:25:55 UTC, Steven Schveighoffer 
wrote:
> On 2/13/15 7:38 AM, tcak wrote:
>> On Friday, 13 February 2015 at 09:38:04 UTC, Dennis Ritchie 
>> wrote:
>>> This is a bug?
>>>
>>> import std.stdio;
>>>
>>> void main() {
>>>    int a = 0;
>>>
>>>    writeln( (a < 10) ? a = 1 : a = 2 );    // prints 2
>>>
>>>    writeln( (a < 10) ? a = 1 : (a = 2) );  // prints 1
>>> }
>>>
>>> Even C++ output:
>>> 1
>>> 1
>>
>> About 2 years ago, I had a problem with similar structure.
>>
>> My guess is that the first one is accepted as this.
>>
>> ((a < 10) ? a = 1 : a)   =   ( 2 )
>>
>> Thereby it gives this result. Vague definitions are always 
>> error prone.
>
> Yes, the operator precedence (curiously not defined in the 
> spec) is here:
>
> http://wiki.dlang.org/Operator_precedence
>
> Conditional operator is above assignment operators.
>
> C++ operator precedence is here:
>
> http://en.wikipedia.org/wiki/Operators_in_C_and_C%2B%2B#Operator_precedence
>
> Note they are the same, but I think C++ ?: = operator in this 
> case does not result in lvalue. So it must be that the = cannot 
> bind to the result of the operator, therefore it binds to the 
> a. Interesting...
>
> -Steve

Thanks.