error value type cannot be assigned to entity type

[iNApoG1T]

I am getting this error message: error value type cannot be assigned to entity type.

Here is my function call: head = data(head);

Here is my function header: ListNode *data(ListNode *head)

[mbozzi]

When asking for help with broken code, it is extremely important to post any error messages, verbatim, even if there are parts that you don't understand or that look like gibberish. It is likely that experts will find the omitted information useful.

I noticed also that you deleted your previous question.
This is considered rude, because it makes it difficult for other users to benefit from the information you were offered.

Please
a.) create a small example which exhibits the problem; and
b.) post that example, along with the exact error messages

http://www.cplusplus.com/forum/beginner/1/
http://www.catb.org/esr/faqs/smart-questions.html