C# generics: cast generic type to value type

Question

I have a generic class which saves value for the specified type T. The value can be an int, uint, double or float. Now I want to get the bytes of the value to encode it into an

Answer 1

Late to the party, but just wanted to comment on the comments saying that the original proposal was a "bad design" - in my opinion, the original proposal (though it doesn't work) was not "necessarily" a bad design at all!

Coming from a strong C++ (03/11/14) background with deep understanding of template meta-programming, I created a type generic serialization library in C++11 with minimal code repetition (the goal is to have non-repetitive code, and I believe I have achieved 99% of it). The compile time template meta-programming facilities as provided by C++11, though can become extremely complex, helps achieve true type generic implementation of the serialization library.

However, it is very unfortunate that when I wanted to implement a simpler serialization framework in C#, I was stuck exactly on the problem that the OP had posted. In C++, the template type T can be totally "forwarded" to the site of usage, while C# generics does not forward the actual compile time type to the usage site - any second (or more) level reference to a generic type T makes T becoming a distinct type that is not usable at all at the actual usage site, thus GetBytes(T) cannot determine that it should invoke a specific typed overload - worse, there is even no nice way in C# to say: hey, I know T is int, and if the compiler doesn't know it, does "(int)T" make it an int?

Also, instead of blaming that type based switch has a smell of bad design - this has been a great misnomer that whenever people are doing some advanced type based framework and has to resort to type based switch due to inability of the language environment, without really understanding the constraints of the actual problem at hand, people starts to blatantly say type based switch is a bad design - it is, for most of the traditional OOP usage cases, but there are special cases, most of the time advanced usage case like the problem we are talking here, that this is necessary.

It is also worth mentioning that I would actually blame that the BitConverter class is designed in a traditional and incompetent way to suit generic needs: instead of defining a type specific method for each type with regard to "GetBytes", maybe it would be more generic friendly to define a generic version of GetBytes(T value) - possibly with some constraints, so the user generic type T can be forwarded and work as expected without any type switch at all! The same is true for all the ToBool/ToXxx methods - if the .NET framework provides the facilities as non-generic version, how would one expect a generic framework trying to utilize this foundation framework - type switch or if without type switch, you end up duplicating the code logic for each data type you are trying to serialize - Oh, I miss the day I worked with C++ TMP that I only write the serialization logic once for practically unlimited number of types I can support.