defined_class

        # TracePoint.defined_class

(from ruby core)
---
    defined_class()

---

Return class or module of the method being called.

    class C; def foo; end; end
    trace = TracePoint.new(:call) do |tp|
      p tp.defined_class #=> C
    end.enable do
      C.new.foo
    end

If method is defined by a module, then that module is returned.

    module M; def foo; end; end
    class C; include M; end;
    trace = TracePoint.new(:call) do |tp|
      p tp.defined_class #=> M
    end.enable do
      C.new.foo
    end

**Note:** #defined_class returns singleton class.

6th block parameter of Kernel#set_trace_func passes original class of
attached by singleton class.

**This is a difference between Kernel#set_trace_func and TracePoint.**

    class C; def self.foo; end; end
    trace = TracePoint.new(:call) do |tp|
      p tp.defined_class #=> #<Class:C>
    end.enable do
      C.foo
    end