refine cpp infer doc

doc/features.drawio

-<mxfile host="app.diagrams.net" modified="2022-04-24T03:27:28.834Z" agent="5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.84 Safari/537.36" etag="5qc2q6KryFO3-qE6nCEb" version="17.4.6" type="device"><diagram id="7VLXkfM5LJYEknv3_pDO" name="Page-1">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</diagram></mxfile>
\ No newline at end of file

doc/test.svg

-<mxfile host="app.diagrams.net" modified="2022-04-24T06:56:35.303Z" agent="5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.84 Safari/537.36" etag="b0kQz9uTd5Ngnqm7Qq4x" version="17.4.6" type="github"><diagram id="prtHgNgQTEPvFCAcTncT" name="Page-1">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</diagram></mxfile>
\ No newline at end of file