[Interest] QVariant compare operator

[evilruff]

With all respect to Thiago opinion I coldnt agree with it. There is nothing wrong at all with forwarding comparison of the values with the same data types to original classes within universal coontainer like QVariant as mentioned in the previous answer. However I agree that comparing uncomparable should lead to qFatal.. Problem is that even if I support idea of clean and tidy architectures and designs -main goal of the frameworks is to make life simple and easier to the end user -  developer.. I looked in 5.15 sources. Ok idea clear - compare logic moved to virtual lessThen of the sortind model with QModelIndex's as parameters. Thats exactly an approach i have in my code for now with all extra switches to handle what was forgotten in QVariant implementation, but as for me its not a way to go. QVariant is a class exists for ages in the Qt and it has all the features even now to provide a decent way to compare typed related objects it contains including custom implementations.As for me 5.15 implementation is not better, its just moving same code to other classes provoking develor to extra inheritance or to copy paste this code to other places where QVariant stored values requires comparation..Why on earth then not to change this in existing branches used in production rather then declare that its a bad desing. I am not even talking about QtScript which is also QVariant based and where it was really convinient way to handle abstract types. I know that answer probably will be that we deprecated QtScript decades ago, but again up to me thats was one on the worsest decision made although its a bit other subject.It would take 15-20 lines of code to add native comparations to already existing classes to current QVariant which will make things consistent where of course < operator is applicable but only answer received sounds more like... ( skipped due to probable violation of some rules).. ;)And as we started about versions.. its nice to hear that something going to change in 5.15, 6.0 etc, but are Qt developers really assume that stable production code will easily 'just go' over major branches to update or will start adjusting current designs to potentially fullfil some guidelines of far away releases? 
Well, if QVariant::canConvert() says right operand can be converted to type of left, thenconvert and compare the result. If it can't convert, behavior should be undefined andqFatal() should be called (or whatever Qt 5.15 prefers to do in detectable cases ofundefined behavior).
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