https://issues.dlang.org/show_bug.cgi?id=20136

          Issue ID: 20136
           Summary: opEquals not recognized for AA key
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: tim.dlang@t-online.de

The following code compiles with dmd 2.086.0, but not with dmd 2.086.1 or dmd 2.088.0-beta.1:

class Context
{
    size_t[const(Key)] aa;
    bool checkAll;
}

struct Key
{
    Context context;
    int i;
    bool opEquals(ref const Key other) const
    {
        if(context.checkAll && i != other.i)
            return false;
        return true;
    }
}

Dmd 2.086.1 prints the following error message:
Error: AA key type Key does not have bool opEquals(ref const Key) const

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