Template namespaces - Obsolete?

[BCS]

Michel Fortin wrote:
> On 2007-09-19 15:23:36 -0400, "Janice Caron" <caron800 at googlemail.com> 
> said:
> 
>> Is there any need, any more, for the old fashioned
>>
>> template t(T)
>> {
>>     int f();
>>     int g();
>> }
> 
> 
> I haven't seen it yet, but templates are very powerful when combined 
> with static if. You can only do that the "old fashioned" way.
> 
> This code is from the D/Objective-C bridge I released yesterday:
> 
> /**
> * Number of arguments in method name. This simply count the number of
> * colon character within the string.
> */
> template methodArgumentCount(char[] name) {
>     static if (name.length == 0) {
>         const uint methodArgumentCount = 0;
>     } else static if (name[0] == ':') {
>         const uint methodArgumentCount = 1 + 
> methodArgumentCount!(name[1..$]);
>     } else {
>         const uint methodArgumentCount = methodArgumentCount!(name[1..$]);
>     }
> }
> 
> 

That reminds me of another uses for the full form

template Foo(bool b)
{
	static if(b)
		alias T!(int, float, char) args;
	else
		alias T!(short byte) args;

	void Bar(args val){}
}


Iv never actually had code where I needed that, but I came close. What I 
ended up with was this:

enum Ver
{
	zero = 0,
	one = 1,
	two = 2
}

T!(byte, short, int)[t] Foo(Ver t)(T!(int, short, byte)[0..t] args){}

I was just lucky enough that the order of the args was the same for all 
cases, just some of them omitted the later ones. (That was some nasty code!)