Error: "Pointers and fixed size buffers may only be used in an unsafe context."

Is it possible to use Mathf.SmoothDamp in C#? I've seen a number of Unityscript examples, but attempting to use the function in C# with an explicit reference to the "currentSpeed" variable brings up an error "Pointers and fixed size buffers may only be used in an unsafe context." I'd rather not run in unsafe mode in case we want to use the webplayer. How should I be calling this function?

The code I'm trying to execute looks like this:

this.newSpeed = Mathf.Clamp (this.newSpeed, 0, throttle * topSpeed);
this._speed = Mathf.SmoothDamp (this._speed, this.newSpeed, & currentVelocity, 1.0f);

and runs inside a coroutine.

I think you're getting that error because of the stray '&' symbol you have in there. SmoothDamp is completely safe to use, and it's the same in c# as it is in Javascript. You just need the 'ref' keyword preceeding the currentVelocity variable (as shown in the function signature, in the docs). eg:

 float newPosition = Mathf.SmoothDamp(current, target, ref currentVelocity, smoothTime);