Testing for template argument being result of takeExactly

[monarch_dodra]

On Monday, 24 September 2012 at 22:13:51 UTC, Timon Gehr wrote:
> On 09/24/2012 09:41 AM, monarch_dodra wrote:
> > [SNIP]
>
> I don't think this does what you think it does. The 'is(R r)' 
> declares r to be an alias for R. So 'r' is a type in that code 
> snippet.

Darn :(

> Also, is(typeof(takeExactly(R, 1))) && is(R == 
> typeof(takeExactly(R, 1)))
>
> can be written in a more compact way as
>
> is(typeof(takeExactly(R, 1)) == R)
>
Technically, no: That was my first try, and as mentioned in the 
first reply, this returns true when the types of takeExactly and 
R are equal comparable, but does not make sure they are the 
actually the same types.

"is(R == typeof(takeExactly(R, 1)))"

Makes sure they are the exact same type, and

"is(typeof(takeExactly(R, 1)))"

is a short-circuit, to prevent the second test from error'ing if 
takeExactly!R is not legal.