Macro vecone 

macro_rules! vecone {
    ($($x:expr),+ $(,)?) => { ... };
    ($elem:expr; $n:expr) => { ... };
}

Creates a VecOne containing the arguments.

vecone! allows VecOnes to be defined with similar syntax to vec!, but with a minimum length of 1. The length must be constant, for non-constant length use checked constructors.