Re: constraints,template specialization,drop IFTI

[Ary Borenszweig]

Daniel Keep wrote:

BLS wrote:

I have somehow the idea that D constraints and template specialization
should merge.
Guess what I want to say is that instead of accepting the  compiler
decision for template specialization  a constraints could be used for :
"I am not the one who is able to fulfill your needs.. try this template
instead."

template Foo(int N)
        if ( ( N & 1 _else_ FooOdd!(int N)) )
{
    ...
}

Firstly, why not

template Foo(int N)
    if( N&1 ) else FooOdd!N
{
    ...
}

Secondly, why?  I mean, isn't this equivalent to:

template Foo(int N)
{
    static if( N&1 ) { ... }
    else alias FooOdd!N Foo;
}

And this?

template Foo(int N) if ((N & 1) != 0)
{
}

template Foo(int N) if ((N & 1) != 1)
{
}