After verification, one of the reasons caused the factors is:
that you declare a function name, and in. H file defines some methods, but not in. CPP implementation inside, this will appear such mistakes.
and the solution can refer to the following:

the above for the nsight eclipse compiler error, as is shown in the display under the compilation instructions. O file is false, do not implement the method can search and in the documents. H file compared to completion.