2017-03-23 16:35 GMT+01:00 sebb <seb...@gmail.com>: > On 23 March 2017 at 15:02, Lukasz Lenart <lukaszlen...@apache.org> wrote: >> 2017-03-23 14:37 GMT+01:00 sebb <seb...@gmail.com>: >>> Not sure I follow. >>> >>> What exactly can the compiler check? >> >> You can declare a variable or a field of type UnmodifiableSet but >> there is no way to create instance of the type UnmodifiableSet - there >> is no such constructor neither factory method :) >> > > You can create an instance: > > UnmodifiableSet<String> us = (UnmodifiableSet<String>) > UnmodifiableSet.unmodifiableSet(new java.util.HashSet<String>());
Hmm... it is a solution ... > us.clear(); // The compiler is happy with this, but it fails at > runtime I don't care, internal code won't use it, if someone will try call clear() it will be they problem ;-) > AFAICT the only way the compiler can check is to create a class or > interface that does not have the update methods. > > One could potentially create a ReadOnlySet interface that is > implemented by UnmodifiableSet. > Similarly for the other unmodifiable Collections. > > However would it be worth it? I think it's worth do such thing, ReadOnlySet speaks better than any JavaDoc :) Regards -- Łukasz + 48 606 323 122 http://www.lenart.org.pl/ --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
