• Johannes Pfau (26/26) Aug 08 2012 I wanted to add a new overload to digest for the std.hash module (see
• Timon Gehr (13/13) Aug 08 2012 Try this:
• Johannes Pfau (6/20) Aug 08 2012 Clever, but doesn't seem to work. I can't create an instance of it, even
• Timon Gehr (5/25) Aug 08 2012 Well, I have done similar things in the past. The general concept should...
• Johannes Pfau (9/19) Aug 09 2012 I see! I didn't have the cast(void[][]) in there. Usually a function
• Johannes Pfau (5/6) Aug 09 2012 Sorry, seems this isn't true. Not sure where I got that information

Johannes Pfau <nospam example.com> writes:

I wanted to add a new overload to digest for the std.hash module (see
review in main newsgroup). This is the code written as two functions
which should be combined in one overloaded function

----------------
digestType!Hash digest(Hash)(scope const(void[])[] data...)
    if(isDigest!Hash)
{
    //implementation detail
}

digestType!Hash digestRange(Hash, Range)(Range data) if(isDigest!Hash &&
    isInputRange!Range && __traits(compiles,
    digest!Hash(ElementType!(Range).init)))
{
    //implementation detail
}
----------------

What I need is two overloads: One which takes a byte representation of
every possible type (and multiple parameters of that), except
InputRanges. And one which handles the InputRanges.
As an additional difficulty the overload taking all other types should
only cause one template instance (per Hash type) to avoid template
bloat (like currently).

It must also be possible to alias the template for specific Hash types
(could be done with a template instead of an alias as long as it doesn't
cause bloat):

alias digest!MD5 md5Of; //Works right now

Timon Gehr <timon.gehr gmx.ch> writes:

Try this:

template digest(Hash) if(isDigest!Hash){
	digestType!Hash digest(Range)(Range data) if(!is(Range:void[][]) && 
isInputRange!Range && 
__traits(compiles,digest!Hash(ElementType!(Range).init))){
		//implementation detail
	}
	digestType!Hash digest()(scope const(void[])[] data...){ // templated 
as a workaround
		//implementation detail
	}
         // ... (maybe more overloads)
}

Johannes Pfau <nospam example.com> writes:

Am Wed, 08 Aug 2012 18:53:05 +0200
schrieb Timon Gehr <timon.gehr gmx.ch>:

 Try this:
 
 template digest(Hash) if(isDigest!Hash){
 	digestType!Hash digest(Range)(Range data)
 if(!is(Range:void[][]) && isInputRange!Range && 
 __traits(compiles,digest!Hash(ElementType!(Range).init))){
 		//implementation detail
 	}
 	digestType!Hash digest()(scope const(void[])[] data...){ //
 templated as a workaround
 		//implementation detail
 	}
          // ... (maybe more overloads)
 }

Clever, but doesn't seem to work. I can't create an instance of it, even
when explicitly specifying the types.

BTW: This is a working version, but it does cause template bloat:
http://dpaste.dzfl.pl/d42a58aa

Timon Gehr <timon.gehr gmx.ch> writes:

On 08/08/2012 09:11 PM, Johannes Pfau wrote:
 Am Wed, 08 Aug 2012 18:53:05 +0200
 schrieb Timon Gehr<timon.gehr gmx.ch>:

 Try this:

 template digest(Hash) if(isDigest!Hash){
 	digestType!Hash digest(Range)(Range data)
 if(!is(Range:void[][])&&  isInputRange!Range&&
 __traits(compiles,digest!Hash(ElementType!(Range).init))){
 		//implementation detail
 	}
 	digestType!Hash digest()(scope const(void[])[] data...){ //
 templated as a workaround
 		//implementation detail
 	}
           // ... (maybe more overloads)
 }

 Clever, but doesn't seem to work.  I can't create an instance of it, even
 when explicitly specifying the types.

Well, I have done similar things in the past. The general concept should 
work.

 BTW: This is a working version, but it does cause template bloat:
 http://dpaste.dzfl.pl/d42a58aa

Maybe this helps:
http://dpaste.dzfl.pl/ed2e8e5d

Johannes Pfau <nospam example.com> writes:

Am Wed, 08 Aug 2012 21:55:21 +0200
schrieb Timon Gehr <timon.gehr gmx.ch>:

 
 Well, I have done similar things in the past. The general concept
 should work.
 
 BTW: This is a working version, but it does cause template bloat:
 http://dpaste.dzfl.pl/d42a58aa

 
 Maybe this helps:
 http://dpaste.dzfl.pl/ed2e8e5d

I see! I didn't have the cast(void[][]) in there. Usually a function
defined with (void[][] data...) can take an arbitrary number of
arguments of any type. But when used as above, it looses that feature
and an explicit cast is necessary.

http://dpaste.dzfl.pl/8bb247ff

Not sure if I like this, I'll probably just have a separate function
digestRange.

Johannes Pfau <nospam example.com> writes:

Am Thu, 9 Aug 2012 10:20:45 +0200
schrieb Johannes Pfau <nospam example.com>:


 arguments of any type.

Sorry, seems this isn't true. Not sure where I got that information
from, void[][]... only works with all array types, not all types in
general.