Select the current code block

To select the current block of C++ code in the code editor, press Ctrl+U.

Press Ctrl+U a second time to extend the selection to the parent block.

To undo the last selection, press Ctrl+Alt+Shift+U.

Turn on smart block selection

To turn on smart block selection, go to Preferences > Text Editor > Behavior and select Enable smart selection changing.

{Text Editor Behavior preferences}

See also How To: Edit Code and Edit Mode.