gistfile1.rs

enum Shape {
    Circle {
        radius: float
    },
    NoShape,
}

fn main() {
    let mut c = Circle{radius: 5.0};
    match c {
        x@Circle{_} => {
            x.radius = 0.0;                                                                                 
            // ERROR                                                                                        
            // main.rs:14:12: 14:20 error: attempted access of field                                        
            // `radius` on type `Shape`, but no field with that                                             
            // name was found
            // main.rs:14 x.radius = 0.0
            //            ^~~~~~~~
	},
	NoShape => (),
    }
}

This is precisely the same error reported when attempting to mutate radius on c:
c.radius = 0.0;