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digitalmars.D.bugs - more templates (and metaprogramming a-la boost)

reply "Carlos Santander B." <carlos8294 msn.com> writes:
In
http://msdn.microsoft.com/visualc/using/understanding/perf/default.aspx?pull=/library/en-us/dv_vstecha
t/html/boostvc.asp, I
found this piece of C++ code:

template< typename T >
class auto_size_example
   : private mpl::if_< sizeof(T) <= sizeof(double)
                     , stack_implementation<T>
                     , heap_implementation<T>
                     >::type
{
  // ...
};

I thought, this can also be done in D, so I tried to. I figured this could
be the way:

template CT (alias cmp, T1, T2)
{
 version (cmp)
  alias T1 S;
 else
  alias T2 S;

 class C : S
 {
 }
}

class C1 (T)
{
}

class C2 (T)
{
}

template T2 ( T )
{
 class C : CT!( T.size < double.size , C1!(T), C2!(T) ).C
 {
 }
}

void main()
{
 T2!(int).C t;
}

However I get "template instance CT!(1,C1 ,C2 ) does not match any template
declaration" (again, no line number, no nothing).
DMD wouldn't let me write "class C : .CT..." (notice the dot before CT), so
I decided to rewrite T2 as:

template T2 ( T )
{
 alias .CT!( T.size < double.size , C1!(T), C2!(T) ).C S;

 class C : S
 {
 }
}

But then I got the horrible:
"Assertion failure: 'id->dyncast() == DYNCAST_IDENTIFIER' on line 2567 in
file 'mtype.c'

abnormal program termination"

-----------------------
Carlos Santander Bernal
May 20 2004
next sibling parent J Anderson <REMOVEanderson badmama.com.au> writes:
Alot of 2567 errors coming up recently.  This has been broken since 
.89.  It's dam annoying when your project just breaks for no good reason.

Your workaround is served cold:

Well I got this much working:

template CT (T1, T2) //Took out the cmp - note this doesn't effect the 
intenal bug
{
class C : S
 {
 }
}

class C1 (T)
{
}

class C2 (T)
{
}

template T2 ( T )
{
    alias .CT CCT;  //The workaround - Prevents internal error
    alias CCT!(C1!(T), C2!(T)).C S;
   
     class C : S
     {
     }
}



void main()
{

    T2!(int).C t;


Carlos Santander B. wrote:

In
http://msdn.microsoft.com/visualc/using/understanding/perf/default.aspx?pull=/library/en-us/dv_vstecha
t/html/boostvc.asp, I
found this piece of C++ code:

template< typename T >
class auto_size_example
   : private mpl::if_< sizeof(T) <= sizeof(double)
                     , stack_implementation<T>
                     , heap_implementation<T>
                     >::type
{
  // ...
};

I thought, this can also be done in D, so I tried to. I figured this could
be the way:

template CT (alias cmp, T1, T2)
{
 version (cmp)
  alias T1 S;
 else
  alias T2 S;

 class C : S
 {
 }
}

class C1 (T)
{
}

class C2 (T)
{
}

template T2 ( T )
{
 class C : CT!( T.size < double.size , C1!(T), C2!(T) ).C
 {
 }
}

void main()
{
 T2!(int).C t;
}

However I get "template instance CT!(1,C1 ,C2 ) does not match any template
declaration" (again, no line number, no nothing).
DMD wouldn't let me write "class C : .CT..." (notice the dot before CT), so
I decided to rewrite T2 as:

template T2 ( T )
{
 alias .CT!( T.size < double.size , C1!(T), C2!(T) ).C S;

 class C : S
 {
 }
}

But then I got the horrible:
"Assertion failure: 'id->dyncast() == DYNCAST_IDENTIFIER' on line 2567 in
file 'mtype.c'

abnormal program termination"

-----------------------
Carlos Santander Bernal


  

-- -Anderson: http://badmama.com.au/~anderson/
May 20 2004
prev sibling parent "C. Sauls" <ibisbasenji yahoo.com> writes:
 template CT (alias cmp, T1, T2)

template CT (int cmp, T1, T2) Just a thought. -C. Sauls -Invironz
May 21 2004