template specialization for arrays

[Steven Schveighoffer]

On Tue, 01 Nov 2011 14:55:45 -0400, J Arrizza <cppgent0 at gmail.com> wrote:

> Steven,
>
> I see,  but here's IsStaticArray from traits.d
>
> template isStaticArray(T : U[N], U, size_t N)
> {
>     enum bool isStaticArray = true;
> }
>
> template isStaticArray(T)
> {
>     enum bool isStaticArray = false;
> }
>
> It looks like the first version is using the "[]" format. It is different
> in that it has the [N] and then goes on to specify that N is a size_t.

Template specification is weird, similar looking things can have  
*completely different* meanings.

The compiler uses a lot of deduction to match template parameters.  There  
are many forms of specialization and comparison.

The equivalent for your case would be:

void abc(T : U[], U) (T parm1)

In other words, "type T is a form of U[], where U is another type".

You should read the spec on how templates work here:

http://www.d-programming-language.org/template.html

Pay close attention to argument deduction.

Another good section to read is the "is expression":

http://www.d-programming-language.org/expression.html#IsExpression

-Steve