class RSpec::Matchers::BuiltIn::BeAnInstanceOf

Not intended to be instantiated directly.
Provides the implementation for ‘be_an_instance_of`.
@api private

def description

Returns:
  • (String) -

Other tags:
    Api: - private 
def description
  "be an instance of #{expected}"
end

def match(expected, actual) 

def match(expected, actual)
  actual.instance_of?(expected)
rescue NoMethodError
  raise ::ArgumentError, "The #{matcher_name} matcher requires that " \
                         "the actual object responds to #instance_of? method " \
                         "but a `NoMethodError` was encountered instead."
end