old_contents: from spack.compiler import *
  import llnl.util.tty as tty
  
  class Nag(Compiler):
      # Subclasses use possible names of C compiler
      cc_names = []
  
      # Subclasses use possible names of C++ compiler
      cxx_names = []
  
      # Subclasses use possible names of Fortran 77 compiler
      f77_names = ['nagfor']
  
      # Subclasses use possible names of Fortran 90 compiler
      fc_names = ['nagfor']
  
      # Named wrapper links within spack.build_env_path
      link_paths = { # Use default wrappers for C and C++, in case provided in compilers.yaml
                     'cc'  : 'cc',
                     'cxx' : 'c++',
                     'f77' : 'nag/nagfor',
                     'fc'  : 'nag/nagfor' }
  
      @property
      def openmp_flag(self):
          return "-openmp"
  
  
      @classmethod
      def default_version(self, comp):
          """The '-V' option works for nag compilers.
             Output looks like this::
  
                 NAG Fortran Compiler Release 6.0(Hibiya) Build 1037
                 Product NPL6A60NA for x86-64 Linux
                 Copyright 1990-2015 The Numerical Algorithms Group Ltd., Oxford, U.K.
          """
          return get_compiler_version(
              comp, '-V', r'NAG Fortran Compiler Release ([0-9.]+)')
  
new_contents: from spack.compiler import *
  import llnl.util.tty as tty
  
  class Nag(Compiler):
      # Subclasses use possible names of C compiler
      cc_names = []
  
      # Subclasses use possible names of C++ compiler
      cxx_names = []
  
      # Subclasses use possible names of Fortran 77 compiler
      f77_names = ['nagfor']
  
      # Subclasses use possible names of Fortran 90 compiler
      fc_names = ['nagfor']
  
      # Named wrapper links within spack.build_env_path
      link_paths = { # Use default wrappers for C and C++, in case provided in compilers.yaml
                     'cc'  : 'cc',
                     'cxx' : 'c++',
                     'f77' : 'nag/nagfor',
                     'fc'  : 'nag/nagfor' }
  
      @property
      def openmp_flag(self):
          return "-openmp"
  
      @property
      def cxx11_flag(self):
          # NAG does not have a C++ compiler
          # However, it can be mixed with a compiler that does support it
          return "-std=c++11"
  
      @classmethod
      def default_version(self, comp):
          """The '-V' option works for nag compilers.
             Output looks like this::
  
                 NAG Fortran Compiler Release 6.0(Hibiya) Build 1037
                 Product NPL6A60NA for x86-64 Linux
                 Copyright 1990-2015 The Numerical Algorithms Group Ltd., Oxford, U.K.
          """
          return get_compiler_version(
              comp, '-V', r'NAG Fortran Compiler Release ([0-9.]+)')
  
subject: add a temporary Nag.cxx11_flag property