Parameter hints show the names of function parameters for the passed arguments. CLion displays them in the editor inlined with your code to improve its readability:
Parameter hints are displayed for argument literals and expressions with more than one operand: function calls, lambdas, initializer lists, macro expressions, and constructors (including the constructors invoked through emplace_back -like functions). Hints for initializers are not shown when the argument is used as a designated initializer.
Arguments passed by non-const reference show the hint &: to indicate the fact they can be modified:
Hide and toggle parameter hints
The hints are enabled by default. To hide them, go to Settings/Preferences | Editor | Inlay Hints | C/C++/Objective-C and clear the Show parameter names hints checkbox.
You can assign a shortcut to quickly toggle the hints on and off. Go to Settings/Preferences | Keymap, search for hints, and add a shortcut for the Toggle parameter name hints action:
Configure parameter hints
To hide parameter hints for particular cases, configure the list of exceptions.
Go to Settings/Preferences | Editor | Inlay Hints | C/C++/Objective-C and click Black list....
Add methods for which you don't want to see the hints.
You can also adjust the hints settings right from the editor:
Press Alt+Enter on a hint to quickly disable it for the current function.
Right-click a hint and select from the list of options.
