fix Issue 16176 - Unreachable code not detected with -w

[WalterBright]

No description provided.

[dlang-bot]

Fix	Bugzilla	Description
✓	16176	Unreachable code not detected with -w

[WalterBright]

That fails miserably because of code like this:

private size_t _clockTypeIdx(ClockType clockType)
{
    final switch(clockType)
    {
        foreach(i, name; __traits(allMembers, ClockType))
        {
        case __traits(getMember, ClockType, name):
            return i;
        }
    }
    assert(0);
}

I may have to give up on this.

[andralex]

Auto-merge toggled on

[WalterBright]

I'm going to abandon this for now. It needs much more careful work, given the weird Duff-like uses that I do not want to break. Besides, I already have another PR to pick up the skipped initializations reliably, so this becomes unimportant.

[JackStouffer]

@WalterBright Are you aware of people asking for you to get rid of this error entirely?

[mathias-lang-sociomantic]

Not entirely. It has some value (Apple's goto fail bug is often mentioned obviously). However, it would be greatly appreciated if it was not issued in the situation mentioned in the P.R. (when it makes templated code harder to write, basically). Also, and even more important, it's a blocker for VRP improvements.