warn/error when static if else ladder has no matching block (or misses "else")

[dlangBugzillaToGithub]

Martin Nowak (@MartinNowak) reported this on 2013-10-29T19:57:05Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=11381

CC List

• Andrej Mitrovic (@AndrejMitrovic)

Description

static if (T.sizeof == 4) { /*A*/ }
else static if (T.sizeof == 8) { /*B*/ }
else static if (T.sizeof == 12) { /*C*/ }

version (Windows) {}
else version (linux) {}
else version (OSX) {}

static if (something) {}
else version (foo) {}
else static if (somethingelse) {}

----

When such a construct is detected and none of the conditional blocks is matched the compiler should warn/error about an unhandled case.
We could also try to make the declaration of such a ladder without an else-clause a warning/error. This would require an explicit "else {}" to achieve the current behavior and avoids inadvertently missing else clauses similar to how non-final switch statements require a default label.

[dlangBugzillaToGithub]

andrej.mitrovich (@AndrejMitrovic) commented on 2013-10-30T08:29:58Z

A somewhat related ER:

http://d.puremagic.com/issues/show_bug.cgi?id=8433