compiler-warning-level-3-c4013.md

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Learn more about: Compiler Warning (level 3) C4013	Compiler Warning (level 3) C4013	11/04/2016	C4013	C4013	9f9afc71-6e78-463d-9d66-3012d6a3cd5d

Compiler Warning (level 3) C4013

'function' undefined; assuming extern returning int

The compiler encountered a call to an undefined function.

To fix by checking the following possible causes

1. Incorrect spelling of function name

2. External functions not prototyped as extern