[Issue 22421] New: static foreach introduces semantic difference between indexing and iteration variable

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22421

          Issue ID: 22421
           Summary: static foreach introduces semantic difference between
                    indexing and iteration variable
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: andrei at erdani.com

Consider the code below. Both versions should work the same, but the second
causes an assertion error.

alias AliasSeq(T...) = T;

version(works)
    template staticMap(alias fun, args...)
    {
        alias staticMap = AliasSeq!();
        static foreach(i; 0 .. args.length)
            staticMap = AliasSeq!(staticMap, fun!(args[i]));
    }
else // BUG below
    template staticMap(alias fun, args...)
    {
        alias staticMap = AliasSeq!();
        static foreach(arg; args)
            staticMap = AliasSeq!(staticMap, fun!arg);
    }


template id(alias what)
{
    enum id = __traits(identifier, what);
}
enum A { a }
static assert(staticMap!(id, A.a) == AliasSeq!("a"));

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