The Expression Inspector is a light-weight version of the Expressions View. It allows you to monitor the values of the highlighted variables or expressions, and manually enter variables or expressions to monitor.
Instead of presenting the information in a view, the Expression Inspector is a floating window. You can have multiple Expression Inspector windows open at one time.
To invoke the Expression Inspector, you need to highlight a variable or expression of interest in the C/C++ editor view, then right-click anywhere in the view and select the Inspect option. If you have not highlighted anything, the Inspect option is unavailable.
You can also manually enter variable names or expressions in the empty field at the bottom of the list.