module RSpec

def self.const_missing(name)
  case name
    when :Matchers
      # Load rspec-expectations when RSpec::Matchers is referenced. This allows
      # people to define custom matchers (using `RSpec::Matchers.define`) before
      # rspec-core has loaded rspec-expectations (since it delays the loading of
      # it to allow users to configure a different assertion/expectation
      # framework). `autoload` can't be used since it works with ruby's built-in
      # require (e.g. for files that are available relative to a load path dir),
      # but not with rubygems' extended require.
      require 'rspec/expectations'
      ::RSpec::Matchers
    else super
  end
end