[GSOC] Database API

[Andrei Alexandrescu]

On 3/26/11 5:33 PM, Kagamin wrote:
> Kagamin Wrote:
>
>> Kagamin Wrote:
>>
>>> Robert Jacques Wrote:
>>>
>>>>> Should be Algebraic!(T, void). If that doesn't currently compile, we
>>>>> should make it compile.
>>>>>
>>>>> Andrei
>>>>
>>>> For what it's worth, both Algebraic!(T, void*) and Algebraic!(T, void)
>>>> compile on my branch of std.variant.
>>>
>>> can't assign null
>>>
>>> 	alias Algebraic!(int,void) nint;
>>> 	nint n1=5;
>>> 	assert(n1==5);
>>> 	n1=null;
>>>
>>> \std\variant.d:497: Error: static assert  "Cannot store a void* in a VariantN!(maxSize,int,void). Valid types are (int, void)"
>>> test.d:45:        instantiated from here: opAssign!(void*)
>>
>> Ahh, there's a workaround:
>>
>> 	alias Algebraic!(int,void) nint;
>> 	nint n1=5;
>> 	assert(n1.get!(int)==5);
>> 	n1=nint(); //uninitialized Variant, sort of null
>> 	assert(!n1.hasValue);
>> 	assert(n1.peek!(int)==null);
>> 	writeln("error here:");
>> 	assert(n1.get!(int)==0);
>
> this also works without allowing void!
>
> 	alias Algebraic!(int) nint;
> 	nint n1=5;
> 	assert(n1.get!(int)==5);
> 	n1=nint(); //still null
> 	assert(!n1.hasValue);
> 	assert(n1.peek!(int)==null);
> 	writeln("error:");
> 	assert(n1.get!(int)==0);

Awesome. Talk about forgetting my own code :o).

Andrei