[Issue 4866] New: Static-to-dynamic converted manifest constant array gets non-converted type in static/constraint if

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=4866

           Summary: Static-to-dynamic converted manifest constant array
                    gets non-converted type in static/constraint if
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Keywords: rejects-valid
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody at puremagic.com
        ReportedBy: rsinfu at gmail.com


--- Comment #0 from Shin Fujishiro <rsinfu at gmail.com> 2010-09-14 11:03:49 PDT ---
If a compile-time constant of type T[N] is converted to a manifest constant of
type T[], then the manifest constant gets a wrong type T[N] in static-if or
template constraints.

In the following code, typeof(dynamic) is correct in static-assert, but wrong
in static-if.
-------------------- test1.d
immutable int[3] statik = [ 1, 2, 3 ];
enum immutable(int)[] dynamic = statik;

static assert(is(typeof(dynamic) == immutable(int)[]));
static if (! is(typeof(dynamic) == immutable(int)[]))
{
    static assert(0);   // (7)
}
pragma(msg, "!! ", typeof(dynamic));
--------------------
% dmd -c -o- test1.d
!! immutable(int[3u])
test1.d(7): Error: static assert  (0) is false
--------------------
Note the pragma output.  Its type is the original static one.

The same happens in template constraint:
-------------------- test2.d
void main()
{
    immutable char[3] statik = "abc";
    enum string dynamic = statik;
    foo(dynamic);   // (5)
}
void foo(T)(T a) if (is(typeof(T) == string)) {}
--------------------
% dmd -c -o- test2.d
test2.d(5): Error: template test2.foo(T) if (is(typeof(T) == string)) does not
match any function template declaration
test2.d(5): Error: template test2.foo(T) if (is(typeof(T) == string)) cannot
deduce template function from argument types !()(string)
--------------------

It's ok if a constant is a scalar:
-------------------- test3.d
immutable int original = 10;
enum real converted = original;

static assert(is(typeof(converted) == real));
static if (! is(typeof(converted) == real)) static assert(0);
--------------------
% dmd -c -o- test3.d
% _
--------------------

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