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digitalmars.D.bugs - [Issue 2056] New: Const system does not allow certain safe casts/conversions involving deep composite types

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2056

           Summary: Const system does not allow certain safe
                    casts/conversions involving deep composite types
           Product: D
           Version: 2.013
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: rejects-valid
          Severity: critical
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: brunodomedeiros+bugz gmail.com


Const system does not allow certain safe casts/conversions involving deep
composite types. In the following example, all casts should be allowed.
----

void testcases()
{
        int[][] intArrayArray;
        int[][][] intArrayArrayArray;


        const(int)[][] f1 = intArrayArray; // Error here
        const(int[])[] f2 = intArrayArray; 

        const(int)[][][] g1 = intArrayArrayArray; // Error here
        const(int[])[][] g2 = intArrayArrayArray; // Error here
        const(int[][])[] g3 = intArrayArrayArray;

}


--
Apr 28 2008
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2056






I'm not sure if I should open a new bug or not, but since this one is still
open, I'll put it here.

The array cases seem to be fixed in DMD 2.14, but the very same problem still
exists with pointer types, for example:

void testcases()
{
        int** intPtrPtr;
        int*** intPtrPtrPtr;

        const(int)** h1 = intPtrPtr; // Error here
        const(int*)* h2 = intPtrPtr;

        const(int)*** i1 = intPtrPtrPtr; // Error here
        const(int*)** i2 = intPtrPtrPtr; // Error here
        const(int**)* i3 = intPtrPtrPtr;

}

Similar issues also exist for associative arrays.


--
May 28 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2056


Bruno Medeiros <bdom.pub+deebugz gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID



12:15:17 PST ---
The latest DMD compiles both code samples now, *however*, I've come to realize
that in fact this code should NOT be allowed (that is, any of the "Error here"
lines in the code above should produce an error), because these casts are
actually not safe.



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Nov 17 2010
prev sibling next sibling parent d-bugmail puremagic.com writes:
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14:21:51 PST ---
So this is a regression?

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Nov 17 2010
prev sibling next sibling parent d-bugmail puremagic.com writes:
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04:06:29 PST ---
A regression? Not exactly. 
When this bug was submitted, the lines marked with "// Error here" did not
compile, and that was the "bug" that was reported. At some point DMD was
changed so that the first, and later both code samples above compiled without
errors. (I don't know if it was because Walter tried to fix this "bug"
specifically, or if it was due to some other DMD changes).

actually invalid, and should not have been fixed in the first place.

( For curiosity, it would only be valid if immutable did not exist, or more
precisely, if T was the only subtype of const(T) )

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Nov 18 2010
prev sibling next sibling parent d-bugmail puremagic.com writes:
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12:11:28 PST ---

 When this bug was submitted, the lines marked with "// Error here" did not
 compile


So what does the fix for bug 3621, I wonder? (It's for dmd 2.038)

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Nov 18 2010
prev sibling parent d-bugmail puremagic.com writes:
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15:20:41 PST ---


 When this bug was submitted, the lines marked with "// Error here" did not
 compile


 
 So what does the fix for bug 3621, I wonder? (It's for dmd 2.038)




not fixed.

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Nov 19 2010