Re: Why an abstract pointer cannot be used as value in an associate array?

[bearophile]

Cheng Wei:

> extern(C) {
> struct ab;
> }
> 
> ab*[int] map;
> 
> void main() {
> map.clear();
> }
> 
> 
> Cannot be compiled. Why?

It's not specific of associative arrays:

extern(C) {
struct AB;
}
AB*[] arr;
void main() {
arr.length += 1;
}

Bye,
bearophile

Why an abstract pointer cannot be used as value in an associate array?

[Cheng Wei]

extern(C) {
struct ab;
}

ab*[int] map;

void main() {
map.clear();
}


Cannot be compiled. Why?

Thanks.

Re: Multithreaded file IO?

[Jerry]

trav...@phare.normalesup.org (Christophe) writes:

> Jerry Quinn , dans le message (digitalmars.D.learn:29763), a écrit :
>> What I really want is a shared fifo where the input is lines from a 
>> file, and many workers grab something from the fifo.  They then push 
>> their results into a shared reordering output queue.
>
> My 2 cent advice:
>
> Does the queue really has to be a file ?
> You could read it completely before starting, and then just share 
> your instructions as strings for example.

Yes, these files could be large enough that the memory cost of loading
is an issue.  Also, I should be able to do this with input from stdin.

At this point, I'm trying to figure out how to implement a shared
fifo in D as much as solve my original problem :-)

Jerry

Re: Using allSatisfy with template that takes multiple type arguments

[Andrej Mitrovic]

Thanks, that works. I'll report the bug as well.

Re: Using allSatisfy with template that takes multiple type arguments

[bearophile]

Andrej Mitrovic:

> But the compiler thinks I'm doing C-style casts so this doesn't work. Any 
> clues?

This seems to work (eye the base of the recursion):

template satisfies(T, alias P) { enum satisfies = P!T; }
 
template anyPredicateSatisfy(T, Preds...) {
static if (Preds.length)
//enum bool anyPredicateSatisfy = (Preds[0]!T) || 
anyPredicateSatisfy!(T, Preds[1 .. $]);
enum bool anyPredicateSatisfy = satisfies!(T, Preds[0]) || 
anyPredicateSatisfy!(T, Preds[1 .. $]);
else
enum bool anyPredicateSatisfy = false;
}
 
template is4(T) { enum is4 = T.sizeof == 4; }
template signed(T) { enum signed = T.min != 0; }
 
static assert(anyPredicateSatisfy!(int, is4, signed));
 
void main() {}


Maybe the error on (Preds[0]!T) is fodder for Bugzilla.

Bye,
bearophile

Re: Using allSatisfy with template that takes multiple type arguments

[Christophe]

Andrej Mitrovic , dans le message (digitalmars.D.learn:29825), a écrit :
> Thanks for the tips guys. I have another similar issue now, I want to
> check whether a type passes any of the predicates I list. This would
> be similar to anySatisfy, however anySatisfy takes one predicate and
> multiple types, and what I need is one type and multiple predicates,
> e.g.:
> 
> anyPredicateSatisfy!(int, isNumeric, isIntegral);
> 
> I've tried copying anySatisfy's code and modifying it to work:
> 
> template anyPredicateSatisfy(T, F...)
> {
> static if (F.length == 0)
> {
> enum bool anySatisfy = false;
> }
> else static if (F.length == 1)
> {
> enum bool anySatisfy = (F[0])!T;
> }
> else
> {
> enum bool anySatisfy = (F[0])!T) || anySatisfy!(T, F[1 .. $]);
  ^ you mean anyPredicateSatisfy
> }
> }
> 
> But the compiler thinks I'm doing C-style casts so this doesn't work. Any 
> clues?