title: How to write json string with utf16 characters in it
body: <p>I'm trying to figure out how to get utf16 characters in my json string.  This is my json:</p>
  
  <pre><code>ourWideStringClass jsonNoError("{    \
      \"type\" : \"ROI\", \
      \"m_position\" : { \
          \"m_x\" : 16, \
          \"m_y\" : 32, \
          \"m_z\" : 0 \
      }, \
      \"m_size\" : { \
          \"m_width\" : 64, \
          \"m_height\" : 128, \
          \"m_depth\" : 3 \
      } \
      } ");
  </code></pre>
  
  <p>So if I have the following utf16, I'm not sure how to put that in the above.  I know I can't put 0x9CE5 in the json, like by replacing 128 with 0x9CE5.  I'm not sure what to do.  Any ideas?</p>
  
  <p>I was reading <a href="https://msdn.microsoft.com/en-us/library/6aw8xdf2.aspx" rel="nofollow noreferrer">encoding U</a>. I'm not sure if I can use the escape U in my json string or how to do that.  Would it be \U"m_x"  ?</p>