[Issue 15153] CTFE failes to access second dimension of static arrays

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15153

ag0aep6g at gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |ag0aep6g at gmail.com
         Resolution|---                         |INVALID

--- Comment #1 from ag0aep6g at gmail.com ---
(In reply to tobias.marstaller from comment #0)
> But even if the array sizes are explicitly given, the error stays:
> 
> -----------------------------------------------------------------------------
> ---
> static int[2][2] staticTable = [[1, 2], [3, 4]];
> static int[2][2] staticallyDerivedTable = deriveTable(staticTable);
> 
> static int[2][2] deriveTable(int[2][2] table)
> {
> 	int nRows = table.length;
> 	int nCols = table[0].length;
> 	int[nCols][nRows] newTable;
> 
> 	// ... do something
> 
> 	return newTable;
> }
> -----------------------------------------------------------------------------
> ---
> 
> 
> This might be related to #2569;
> 
> AFAICT my code is correct; in both cases the required information is
> available
> at compile time. table.length does not throw an error so i guess the basics
> are working fine already.

It's true that table.length is a static value. It's known at compile time, and
the compiler is aware of that. You can use it for static array lengths.

But nRows is a run time variable. Its value may actually be a compile time
constant, but the compiler doesn't try to find out. This is working as
designed.

You can use enums instead of variables:
----
enum int[2][2] staticTable = [[1, 2], [3, 4]];
static int[2][2] staticallyDerivedTable = deriveTable(staticTable);

static int[2][2] deriveTable(int[2][2] table)
{
    enum size_t nRows = table.length;
    enum size_t nCols = table[0].length;
    int[nCols][nRows] newTable;

    // ... do something

    return newTable;
}
----

I'm closing this as INVALID. Please reopen and/or make a thread on
http://forum.dlang.org/group/general if you disagree.

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