public protocol GLmathType : MutableCollectionType {
    typealias Element
}

// This is ok
public func any<bvec:GLmathType>(x:bvec) -> Bool {
        return x.reduce(false) { $0 || $1 as! Bool }
}

// SIL verification failed: entry point has wrong number of arguments
public func any<bvec:GLmathType where
    bvec.Generator.Element:BooleanType,
    bvec.Element == Bool
    >(x:bvec) -> bvec.Element {
        return x.reduce(false) { $0 || $1 }
}