What Does Putting Two Constant Signs On A Function Parameter Do?

Question

I was wondering what two constant signs on a function parameter does in this case?

void virtual_via_pointer( const Employee * const );

Answer 1

This isn't specific to function parameters.

const Employee*

Means a "mutable pointer to a constant instance of Employee".

Employee* const

Means a "constant pointer to a mutable instance of Employee".

const Employee* const

Means a "constant pointer to a constant instance of Employee".

See also the Spiral Rule.

Answer 2

The pointer and the pointee are both constant.