matches?

# File lib/spec/matchers/throw_symbol.rb, line 11
      def matches?(given_proc)
        begin
          if @expected_symbol.nil?
            given_proc.call
          else
            @caught_arg = catch :proc_did_not_throw_anything do
              catch @expected_symbol do
                given_proc.call
                throw :proc_did_not_throw_anything, :nothing_thrown
              end
            end
            @caught_symbol = @expected_symbol unless @caught_arg == :nothing_thrown
          end

        # Ruby 1.8 uses NameError with `symbol'
        # Ruby 1.9 uses ArgumentError with :symbol
        rescue NameError, ArgumentError => e
          raise e unless e.message =~ /uncaught throw (`|\:)([a-zA-Z0-9_]*)(')?/
          @caught_symbol = $2.to_sym

        ensure
          if @expected_symbol.nil?
            return !@caught_symbol.nil?
          else
            if @expected_arg.nil?
              return @caught_symbol == @expected_symbol
            else
              return (@caught_symbol == @expected_symbol) & (@caught_arg == @expected_arg)
            end
          end
        end
      end