module RSpec::Matchers::DSL

def warn_about_block_args(name, declarations)
  declarations.parameters.each do |type, arg_name|
    next unless type == :block
    RSpec.warning("Your `#{name}` custom matcher receives a block argument (`#{arg_name}`), " \
                  "but due to limitations in ruby, RSpec cannot provide the block. Instead, " \
                  "use the `block_arg` method to access the block")
  end
end