why properties don't support +=, -= ... operators?

[Stanislav Blinov via Digitalmars-d]

On Tuesday, 23 May 2017 at 16:13:19 UTC, Andrey wrote:
> Hello! I am constantly worried about this flaw, why this bug 
> still was not resolved: 
> https://issues.dlang.org/show_bug.cgi?id=8006
> e.g. in Kotlin I can write property like this:
>> class Example {
>>     var value: Int = 0
>>         set(v) {
>>             field = v
>>         }
>>         get() = field
>> }
>>
>> fun main() {
>>     var e = Example()
>>     e.value = 10
>>     e.value += 1
>>     println(e.value)
>
> And it will work!
>
> In D I can write something like this:
>> class Example {
>>     private int value_; @property {
>>         void value(in int val) {
>>             value_ = val;
>>         }
>>         int value() {
>>             return value_;
>>         }
>>     }
>> }
>
> That's great, but еhe absence of in-place operators creates 
> additional problems sometimes, and using ref I think not a good 
> idea, because of inconsistency.

struct Foo
{
     private int value_;

     void value(int v) { value_ = v; }
     ref inout(int) value() inout { return value_; }
}

void main()
{
     import std.stdio;
     Foo foo;
     foo.value += 150;
     writeln(foo.value);
}

Which inconsistency do you mean? Not calling a function when 
applying an operator to a property?