• via Digitalmars-d-bugs (46/49) Jun 27 2015 https://issues.dlang.org/show_bug.cgi?id=14740

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=14740

          Issue ID: 14740
           Summary: __traits(allMembers) returns erroneous 'this' member
                    for types declared in functions.
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: Mihail.K fimu.tk

__traits(allMembers) returns an additional non-existent member named 'this' for
types declared inside of functions.

-----

struct Foo
{
    this(int x, int y)
    {
    }
}

void main()
{
    struct Bar
    {
        this(int x, int y)
        {
        }
    }

    pragma(msg, __traits(allMembers, Foo)); // => __ctor
    pragma(msg, __traits(allMembers, Bar)); // => __ctor, this

    foreach(name; __traits(allMembers, Bar))
    {
        import std.stdio : writeln;
        typeof(__traits(getMember, Bar, name)).stringof.writeln;
    }
}

-----

$ dmd -run demo.d
 tuple("__ctor")
 tuple("__ctor", "this")
 demo.d(24): Error: no property 'this' for type 'Bar'

Note the extra member produced by __traits(allMembers, Bar), eventually leading
to a compilation error when referred to by __traits(getMember).

This is likely an oversight or error and should be removed as it serves no
purpose, and can cause problems when iterating over members of a type.

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