old_contents: # -*- coding: utf-8 -*-
  
  from IPython.core.display import Javascript, HTML, display_javascript, display_html
  
  
  def setup_notebook():
      # assign text/x-c++src MIME type to pybind11 cells
      code = """
      require(['notebook/js/codecell'], function(cc) {
          cc.CodeCell.options_default.highlight_modes['magic_text/x-c++src'] =
              {reg: [/^\s*%%pybind11/]};
      });
      """
      display_javascript(Javascript(data=code))
  
      # assign non-black colour to C/C++ keywords
      html = """
      <style>
      .cm-s-ipython span.cm-variable-3 {
          color: #208ffb;
      }
      </style>
      """
      display_html(HTML(data=html))
  
new_contents: # -*- coding: utf-8 -*-
  
  from IPython.core.display import Javascript, HTML, display_javascript, display_html
  
  
  def setup_notebook():
      # assign text/x-c++src MIME type to pybind11 cells
      code = """
      require(['notebook/js/codecell'], function(cc) {
          cc.CodeCell.options_default.highlight_modes['magic_text/x-c++src'] =
              {reg: [/^\s*%%pybind11/]};
      });
      """
      display_javascript(Javascript(data=code))
  
      # assign non-black colour to C/C++ keywords
      html = """
      <style>
      .cm-s-ipython span.cm-variable-3 {
          color: #208ffb;
          font-weight: bold;
      }
      </style>
      """
      display_html(HTML(data=html))
  
subject: make C/C++ keywords bold