Error with constraints on a templated fuction

[via Digitalmars-d-learn]

On Monday, 25 August 2014 at 17:05:48 UTC, H. S. Teoh via 
Digitalmars-d-learn wrote:
> On Mon, Aug 25, 2014 at 03:48:10PM +0000, Jeremy DeHaan via 
> Digitalmars-d-learn wrote:
>> I've done things like this before with traits and I figured 
>> that this way
>> should work as well, but it gives me errors instead. Perhaps 
>> someone can
>> point out my flaws.
>> 
>> immutable(T)[] toString(T)(const(T)* str)
>> 	if(typeof(T) is dchar)//this is where the error is
>
> The correct syntax is:
>
> 	if (is(typeof(T) == dchar))

Almost... T is already a type; typeof(T) doesn't compile.