[].should include_such_that {|item| p(item) }

it_should_include_such_that.patch

commit e5e4aebccc334809c355b7387dc1469e18be2377
Author: Sam Stokes <sam@rapportive.com>
Date:   Wed Oct 5 17:02:47 2011 -0700

    [2, 4, 6].should_not include_such_that(&:odd?)

diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index c6b006b..03aeec5 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -19,6 +19,7 @@ Spec::Runner.configure do |config|
   config.include WebMock::API
   config.include DataModelMatchers
   config.include HashMatchers
+  config.include EnumerableMatchers
   config.include StringMatchers
 
   # If you're not using ActiveRecord you should remove these
diff --git a/spec/support/enumerable_matchers.rb b/spec/support/enumerable_matchers.rb
new file mode 100644
index 0000000..331fcbb
--- /dev/null
+++ b/spec/support/enumerable_matchers.rb
@@ -0,0 +1,46 @@
+module EnumerableMatchers
+  def include_such_that(predicate = nil, &block)
+    IncludeSuchThatMatcher.new(predicate, &block)
+  end
+  class IncludeSuchThatMatcher < Spec::Matchers::Matcher
+    def initialize(predicate = nil, &block)
+      predicate ||= block
+      raise ArgumentError, '".should include_such_that" takes a predicate (must use {} not do/end)' unless predicate.respond_to?(:call)
+
+      super :include_such_that do
+        match do |actual|
+          @passing = actual.select do |item|
+            begin
+              if item.is_a?(Array)
+                predicate.call(*item)
+              else
+                predicate.call(item)
+              end
+            rescue Spec::Expectations::ExpectationNotMetError
+              false
+            end
+          end
+          !@passing.empty?
+        end
+
+        failure_message_for_should do |actual|
+          "expected #{actual.class} to include an entry passing the predicate, but did not"
+        end
+
+        failure_message_for_should_not do |actual|
+          "expected #{actual.class} not to include any entries passing the predicate, but included #{@passing.map(&:inspect).join(', ')}"
+        end
+      end
+    end
+
+    def matches?(actual)
+      raise_block_syntax_error if block_given?
+      super
+    end
+
+    private
+    def raise_block_syntax_error
+      raise MatcherError, 'block passed to should or should_not include_such_that must use {} instead of do/end'
+    end
+  end
+end