Bug 22384 – castSwitch confused by noreturn handlers

castSwitch allows handlers that neither return a value nor throw an exception - as long as no other handler returns a value. This breaks when passing noreturn handlers, causing castSwitch to throw an exception for the void handlers that don't trow an exception and hence being inferred as noreturn. Example void main() { static void objectSkip(Object) {} static void defaultSkip() {} static noreturn objectError(Object) { assert(false); } static noreturn defaultError() { assert(false); } { alias test = castSwitch!(objectSkip, defaultError); static assert(is(ReturnType!test == void)); // fails, noreturn }{ alias test = castSwitch!(objectError, defaultSkip); static assert(is(ReturnType!test == void)); // fails, noreturn }{ alias test = castSwitch!(objectError, defaultError); static assert(is(ReturnType!test == noreturn)); // valid } }

@MoonlightSentinel created dlang/phobos pull request #8270 "Fix 22384 - Treat noreturn handlers like void in castSwitch" fixing this issue: - Fix 22384 - Treat noreturn handlers like void in castSwitch The previous check assumed that non-`void` return implies a returned value - which obviously does not apply for `noreturn`. Further code then assumed that `void` handlers should throw an exception and hence threw an error when it didn't throw. https://github.com/dlang/phobos/pull/8270

dlang/phobos pull request #8270 "Fix 22384 - Treat noreturn handlers like void in castSwitch" was merged into master: - 3e70aac3ae35a26ec837ce5362711ed3bfece2ae by MoonlightSentinel: Fix 22384 - Treat noreturn handlers like void in castSwitch The previous check assumed that non-`void` return implies a returned value - which obviously does not apply for `noreturn`. Further code then assumed that `void` handlers should throw an exception and hence threw an error when it didn't throw. https://github.com/dlang/phobos/pull/8270