is(T : long) vs is(T == long)

[David Nadlinger]

On 3/26/11 12:36 PM, Caligo wrote:
> What is the difference between this:
> template isNumerik(T){
>    enum bool isNumerik = is(T : long) || is(T : real);
> }
>
> and this:
>
> template isNumerik(T){
>    enum bool isNumerik = is(T == long) || is(T == real);
> }
>
>
> They both work and I can't find anywhere in the book where it talks about the :

When in doubt, RTFM: 
http://digitalmars.com/d/2.0/expression.html#IsExpression

(Using the colon allows implicit conversion, while == requires the types 
to be exactly the same)

David