You can select an element name in your code and quickly navigate to its declaration.
Open declaration will attempt to navigate to the exact definition of the selected element if the selected element is a reference or a declaration.
Otherwise, it will attempt to navigate to a declaration of the selected element.
Open declaration requires your file to have the proper include paths set up to the declaration.
If for any reason open declaration cannot find the declaration, it will display the following message in the status line: