CLion 2022.3 Help

Extract function

The following demo illustrates the usage of the Extract function refactoring, as well as Extract parameter, Extract lambda parameter, and Live templates:

When the Extract Function refactoring is invoked, CLion analyses the selected block of code and detects variables that are the input for the selected code fragment and the variables that are output for it.

The detected output variable is used as a return value for the extracted function.

C++ Example



int main() { int x = 15; int y = 10; int z = x - y; return 0; }
int main() { int x = 10; int y = 15; int z = XSubY(x,y); return 0; } void XSubY(int x, int y) { return x - y; }

Extract a function

  1. In the editor, select a block of code to be transformed into a function.

  2. From the main menu or from the context menu of the selection, choose Refactor | Extract | Method or press Ctrl+Alt+M.

  3. In the Extract Function dialog that opens, specify the name of the new function.

  4. Specify the return type of the function.

  5. If the function has not been yet declared, select declaration place: above or below current place.

  6. In the parameters pane:

    • Add the new parameters or delete the unnecessary ones

    • Rename parameters or/and change their types by clicking the corresponding parameter lines and entering the new names and types

    • Reorder parameters in the list

    • Change the return type of the function

  7. Check the result in the Signature Preview pane and click Extract to create the function.

    The selected code fragment will be replaced with a function call.

    Extract method dialog

Last modified: 28 September 2022