ref is unsafe

[Jason House]

On Thursday, 3 January 2013 at 05:56:27 UTC, Timon Gehr wrote:
> On 01/03/2013 12:48 AM, Jason House wrote:
>> ...
>>
>>>
>>> ref int bar()
>>> {
>>>    int i = 7;
>>>    return foo(i);
>>> }
>>
>> If @safe, this code will not compile.
>> Error: foo may return a local stack variable
>> Since "i" is a local variable, "foo(i)" might return it.
>>
>>
>>>
>>> ref int baz(int i)
>>> {
>>>    return foo(i);
>>> }
>>
>> This function is fine. "i" is an input argument so "foo(i)" is
>> considered to be equivalent to an input argument.
>>
>
> Those two cases are pretty much the same.

If what I suggest is done, they must be differentiated. If you 
replace "return foo(i)" with "return i", the compiler will 
already issue an error for the local variable case.