32% Faster Object#try

Here’s the micro benchmark:

```ruby
module ActiveSupport
  module NewTryable #:nodoc:
    def try(*a, &b)
      return unless a.empty? || respond_to?(a.first)
      return public_send(*a, &b) unless a.empty?

      return nil unless block_given?
      return instance_eval(&b) if b.arity == 0
      yield self
    end

    def try!(*a, &b)
      return public_send(*a, &b) if !a.empty?
      return nil unless block_given?
      return instance_eval(&b) if b.arity == 0
      yield self
    end
  end
end


module ActiveSupport
  module OldTryable #:nodoc:
    def try(*a, &b)
      try!(*a, &b) if a.empty? || respond_to?(a.first)
    end

    def try!(*a, &b)
      if a.empty? && block_given?
        if b.arity == 0
          instance_eval(&b)
        else
          yield self
        end
      else
        public_send(*a, &b)
      end
    end
  end
end

class FooNew
  include ActiveSupport::NewTryable

  def foo
  end
end

class FooOld
  include ActiveSupport::OldTryable

  def foo
  end
end 


foo_new = FooNew.new
foo_old = FooOld.new

require 'benchmark/ips'

Benchmark.ips do |x|
  x.report("old") { foo_old.try(:foo) }
  x.report("new") { foo_new.try(:foo) }
  x.compare!
end

# Warming up --------------------------------------
#                  old   144.178k i/100ms
#                  new   172.371k i/100ms
# Calculating -------------------------------------
#                  old      2.181M (± 8.0%) i/s -     10.813M in   5.001419s
#                  new      2.889M (± 7.7%) i/s -     14.479M in   5.051760s

# Comparison:
#                  new:  2888691.7 i/s
#                  old:  2180740.7 i/s - 1.32x  slower
```

Also reduces memory. On https://www.codetriage.com i’m seeing 1.5% fewer object allocations per request (in object count).

Before:

Total allocated: 1014475 bytes (8525 objects)

After:

Total allocated: 1015499 bytes (8389 objects)

1 files changed, 10 insertions, 1 deletions

diff --git a/activesupport/lib/active_support/core_ext/object/try.rb b/activesupport/lib/active_support/core_ext/object/try.rb
index c874691629..bd841771ce 100644
--- a/activesupport/lib/active_support/core_ext/object/try.rb
+++ b/activesupport/lib/active_support/core_ext/object/try.rb
@@ -5,7 +5,16 @@ require "delegate"
 module ActiveSupport
   module Tryable #:nodoc:
     def try(*a, &b)
-      try!(*a, &b) if a.empty? || respond_to?(a.first)
+      return unless a.empty? || respond_to?(a.first)
+      if a.empty? && block_given?
+        if b.arity == 0
+          instance_eval(&b)
+        else
+          yield self
+        end
+      else
+        public_send(*a, &b)
+      end
     end
 
     def try!(*a, &b)