Read-only property without @property

[Andrei Alexandrescu via Digitalmars-d]

On 9/26/14, 5:58 PM, H. S. Teoh via Digitalmars-d wrote:
> On Fri, Sep 26, 2014 at 07:32:49PM -0400, Steven Schveighoffer via Digitalmars-d wrote:
>> On 9/26/14 6:32 PM, H. S. Teoh via Digitalmars-d wrote:
>>
>>> Does the compiler infer it as @safe, though?
>>
>> Hm... good point, I'm not sure if unions are considered @safe. But I
>> think that would be a decent enhancement request if not.
> [...]
>
> 	union U {
> 		int* ptr;
> 		long i;
> 	}
>
> 	void main() @safe {
> 		U u;
> 		u.i = 12345;
> 		*u.ptr = 54321; // this can't possibly be @safe
> 	}
>
> How would the compiler decide which union operations are @safe and which
> are not?

Unions mixing pointers and integrals aren't safe. Those mixing e.g. a 
float and an int are. -- Andrei