old_contents: {
      "targets": [{
          "target_name": "mmap-io",
          "sources": [ "src/mmap-io.cc" ],
          "include_dirs": [
              "<!(node -e \"require('nan')\")"
          ],
          "cflags_cc": [
              "-std=c++0x"
          ]
      }]
  }
  
new_contents: {
      "targets": [{
          "target_name": "mmap-io",
          "sources": [ "src/mmap-io.cc" ],
          "include_dirs": [
              "<!(node -e \"require('nan')\")"
          ],
          "cflags_cc": [
              "-std=c++11"
          ]
      }]
  }
  
subject: change back to -std=c++11