I want to create a static array large enough to store 1MB of float values.
What am I doing wrong?
Here is a sample code with notes:

void main(string[] args) {
	enum size_t COUNT = 1024 * 512 / float.sizeof; // works OK :)
	//enum size_t COUNT = 1024 * 512 * 2 / float.sizeof; // constantly crashes :(
	float[COUNT] arr;
	writeln(arr.length);
}

DMD: 2069.2
OS: Win 8.1 Pro

On Saturday, 5 December 2015 at 09:49:06 UTC, ref2401 wrote:
> I want to create a static array large enough to store 1MB of float values.
> What am I doing wrong?
> Here is a sample code with notes:
>
> void main(string[] args) {
> 	enum size_t COUNT = 1024 * 512 / float.sizeof; // works OK :)
> 	//enum size_t COUNT = 1024 * 512 * 2 / float.sizeof; // constantly crashes :(
> 	float[COUNT] arr;
> 	writeln(arr.length);
> }
>
> DMD: 2069.2
> OS: Win 8.1 Pro

I suppose you overflow the stack.
I am not a Windows dev, but I suppose there is a linker option to increase the stack size.
Or you can try to use a global __gshared variable or allocate your array on the heap.

On Saturday, 5 December 2015 at 09:49:06 UTC, ref2401 wrote:
> I want to create a static array large enough to store 1MB of float values.
> What am I doing wrong?
> Here is a sample code with notes:
>
> void main(string[] args) {
> 	enum size_t COUNT = 1024 * 512 / float.sizeof; // works OK :)
> 	//enum size_t COUNT = 1024 * 512 * 2 / float.sizeof; // constantly crashes :(
> 	float[COUNT] arr;
> 	writeln(arr.length);
> }
>
> DMD: 2069.2
> OS: Win 8.1 Pro

The default stack size is probably 1MB, which means your 1MB array plus a few local variables is too much. Arrays that large should be allocated on the heap in most circumstances.

Watch out for this:
static assert(is(typeof(new float[3]) == float[]));
because `new T[n]` is a special case in the grammar. If you really must have a static array on the heap (as opposed to a dynamic array / slice T[]), you can use something like this, but i wouldn't recommend it:

T[N]* heapStaticArray(T, size_t N)()
{
    return cast(T[N]*)((new T[N]).ptr);
}

void main()
{
	int[4]* a = heapStaticArray!(int, 4)();
	(*a)[] = 3;
}

On 12/5/15 8:09 AM, John Colvin wrote:
> On Saturday, 5 December 2015 at 09:49:06 UTC, ref2401 wrote:
>> I want to create a static array large enough to store 1MB of float
>> values.
>> What am I doing wrong?
>> Here is a sample code with notes:
>>
>> void main(string[] args) {
>>     enum size_t COUNT = 1024 * 512 / float.sizeof; // works OK :)
>>     //enum size_t COUNT = 1024 * 512 * 2 / float.sizeof; // constantly
>> crashes :(
>>     float[COUNT] arr;
>>     writeln(arr.length);
>> }
>>
>> DMD: 2069.2
>> OS: Win 8.1 Pro
>
> The default stack size is probably 1MB, which means your 1MB array plus
> a few local variables is too much. Arrays that large should be allocated
> on the heap in most circumstances.
>
> Watch out for this:
> static assert(is(typeof(new float[3]) == float[]));
> because `new T[n]` is a special case in the grammar. If you really must
> have a static array on the heap (as opposed to a dynamic array / slice
> T[]), you can use something like this, but i wouldn't recommend it:
>
> T[N]* heapStaticArray(T, size_t N)()
> {
>      return cast(T[N]*)((new T[N]).ptr);
> }
>
> void main()
> {
>      int[4]* a = heapStaticArray!(int, 4)();
>      (*a)[] = 3;
> }

T[N]* heapStaticArray(T, size_t N)()
{
   auto arr = new T[N][1];
   return &arr[0];
}

-Steve