I've got:
alias ProgramResultsQueue(O,I) = BinaryHeap!(Array!(Results!(O,I)), compareResults);

outside the class ProgramOptimizer.  Inside the class I have:

ProgramResultsQueue!(O,I) programResultsQ = heapify!(compareResults, Array!(Results!(O,I)))(Array!(Results!(O,I)), 0);

at class scope (not in a function or ctor).

Error:
cannot pass type Array!(Results(int,float)) as a function argument.  When I add () to Array!(Results!(O,I)) I get some weird error in the library that can't be helped either.

Please guide me!

It is much more efficient if you can show the problem in minimal code. :)

Here is minimal code that demonstrates the problem:

import std.container;

struct Results(O, I)
{}

bool compareResults(O, I)(Results!(O, I) lhs, Results!(O, I) rhs)
{
    return lhs == rhs;
}

alias ProgramResultsQueue(O,I) =
    BinaryHeap!(Array!(Results!(O,I)), compareResults);

class ProgramOptimizer(O, I)
{
    ProgramResultsQueue!(O,I) programResultsQ =
        heapify!(compareResults, Array!(Results!(O,I)))(Array!(Results!(O,I)),
                                                        0);
}

void main()
{
    auto p = new ProgramOptimizer!(int, float);
}

On 09/21/2015 04:37 PM, Enjoys Math wrote:
>
> I've got:
> alias ProgramResultsQueue(O,I) = BinaryHeap!(Array!(Results!(O,I)),
> compareResults);
>
> outside the class ProgramOptimizer.  Inside the class I have:
>
> ProgramResultsQueue!(O,I) programResultsQ = heapify!(compareResults,
> Array!(Results!(O,I)))(Array!(Results!(O,I)), 0);
>
> at class scope (not in a function or ctor).

You cannot execute code inside the body of a class other than simple initialization of members when it's possible to do so at compile time. In general, members are initialized in the constructor.

> Error:
> cannot pass type Array!(Results(int,float)) as a function argument.

You are passing 'types' but heapify's function parameter takes a storage and an initial size:

  http://dlang.org/phobos/std_container_binaryheap.html#.heapify

(Types cannot be function arguments anyway.)

> When I add () to Array!(Results!(O,I)) I get some weird error in the
> library that can't be helped either.
>
> Please guide me!

The following at least compiles:

import std.container;

struct Results(O, I)
{}

bool compareResults(O, I)(Results!(O, I) lhs, Results!(O, I) rhs)
{
    return lhs == rhs;
}

alias ProgramResultsQueue(O,I) =
    BinaryHeap!(Array!(Results!(O,I)), compareResults);

class ProgramOptimizer(O, I)
{
    Array!(Results!(O, I)) store;
    ProgramResultsQueue!(O,I) programResultsQ;

    this()
    {
        programResultsQ =
            heapify!(compareResults, Array!(Results!(O,I)))(store, 100);
    }
}

void main()
{
    auto p = new ProgramOptimizer!(int, float);
}

Ali