yank unary '+'?

[Don]

KennyTM~ wrote:
> On Dec 7, 09 04:30, Don wrote:
>> KennyTM~ wrote:
>>> On Dec 7, 09 00:23, Andrei Alexandrescu wrote:
>>>> Is there any good use of unary +? As an aside, Perl programs do use it
>>>> occasionally for syntactic disambiguation :o).
>>>>
>>>> Andrei
>>>
>>> Yes, when you want to port the Boost Spirit parser :o) (OK that's an
>>> abuse.)
>>>
>>> Well the unary + can help to emphasize "it's a positive number", and
>>> 1.0e+10 is already a form of "unary +" (not the operator).
>>>
>>> Removing the unary + doesn't lose much, but it doesn't gain much
>>> either, and with it already present in all other languages, I don't
>>> see a good reason to change it.
>>
>> I think + should be added to the syntax for numeric literals, and in all
>> other cases unary + should be dropped.
>> Ie,
>> x = +0.78; should remain legal.
>> But
>> y = +x; should not.
>> And likewise,
>> x = +(+0.78); should be illegal.
>>
>> Overloading + is odd, too. Currently:
>> +x;
>> creates a "has no effect" error if x is a built-in type. But if x has an
>> overloaded unary +, it might have side-effects. So it useful ONLY for
>> operator abuse!
>>
>>
> 
> import std.math;
> 
> auto theta1 = +PI/6;
> auto theta2 = -PI/8;

Good one.