Prefer string patterns for gsub

https://github.com/ruby/ruby/pull/579 - there is a new optimization
since ruby 2.2

Previously regexp patterns were faster (since a string was converted to
regexp underneath anyway). But now string patterns are faster and
better reflect the purpose.

  Benchmark.ips do |bm|
    bm.report('regexp') { 'this is ::a random string'.gsub(/::/, '/') }
    bm.report('string') { 'this is ::a random string'.gsub('::', '/') }
    bm.compare!
  end
  # string: 753724.4 i/s
  # regexp: 501443.1 i/s - 1.50x slower

1 files changed, 1 insertions, 1 deletions

diff --git a/actionview/lib/action_view/template/handlers/raw.rb b/actionview/lib/action_view/template/handlers/raw.rb
index 397c86014a..0c0d1fffcb 100644
--- a/actionview/lib/action_view/template/handlers/raw.rb
+++ b/actionview/lib/action_view/template/handlers/raw.rb
@@ -2,7 +2,7 @@ module ActionView
   module Template::Handlers
     class Raw
       def call(template)
-        escaped = template.source.gsub(/:/, '\:')
+        escaped = template.source.gsub(':', '\:')
 
         '%q:' + escaped + ':;'
       end