Creating a custom method of a System Type

Question

I am just curious if there is a way of adding a method to the system type ie

char.IsNull(value) 

i know a similar thing can be achieved by using an extension method but to call that i have to put 'M'.IsNull()

Answer 1

No, basically; there is an ongoing discussion (titled "extension everything") on the topic of whether to add such a feature, but right now (including the current C# 8 previews): no.