```ruby
# ext/baz/extconf.rb
require 'mkmf'
$CXXFLAGS = '--std=c++0x'
create_makefile( 'baz/baz' )
```

Revert - worked locally, but on Travis it seems . . .
user
```ruby
# ext/baz/extconf.rb
require 'mkmf'
create_makefile( 'baz/baz' )
```
assistant