November 02, 2015
https://issues.dlang.org/show_bug.cgi?id=15279

ag0aep6g@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ag0aep6g@gmail.com

--- Comment #1 from ag0aep6g@gmail.com ---
I don't think this is an issue with dchar/char. The same happens with int:

----
void main() {
    int d;

    switch (d) {
    case 0: .. case 0x0101:
        break;
    }
}
----

Looks like more than 256 cases are not supported.

--
September 08
https://issues.dlang.org/show_bug.cgi?id=15279

Dennis <dkorpel@live.nl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dkorpel@live.nl
           Hardware|x86_64                      |All
            Summary|dchar is treated as char in |increase 256 switch case
                   |case range                  |range limit
                 OS|Linux                       |All
           Severity|normal                      |enhancement

--- Comment #2 from Dennis <dkorpel@live.nl> ---
You're hitting a limit that was set in place because the current implementation doesn't scale well to larger ranges, see: https://github.com/dlang/dmd/pull/12002

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