Overloading + on Option

Compiler error

compile_and_link: x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/libcore.so
/media/linhaus/rust/src/libcore/option.rs:331:46: 331:48 error: mismatched types: expected `'a` but found `'b` (expected type parameter but found type parameter)
/media/linhaus/rust/src/libcore/option.rs:331             (Some(v1), Some(v2)) => Some(v1 + v2)
                                                                                            ^~
/media/linhaus/rust/src/libcore/option.rs:331:36: 332:9 error: mismatched types: expected `option::Option<'b>` but found `option::Option<'a>` (expected type parameter but found type parameter)
/media/linhaus/rust/src/libcore/option.rs:331             (Some(v1), Some(v2)) => Some(v1 + v2)
/media/linhaus/rust/src/libcore/option.rs:332         }
error: aborting due to 2 previous errors
make: *** [x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/libcore.so] Error 101

option.rs

impl<R,T: Add<R,R>> Option<T> : Add<Option<T>, Option<T>> {
    #[inline(always)]
    pure fn add(other: &Option<T>) -> Option<T> {
        match (self, *other) {
            (None, None) => None,
            (_, None) => self,
            (None, _) => *other,
            (Some(v1), Some(v2)) => Some(v1 + v2)
        }
    }
}