Trait UniqueValue 

pub unsafe trait UniqueValue {
    // Required method
    fn get_unique(&self) -> Option<&str>;
}

Return a reference to value in a collection if it is the only one.

For example, a vector of string like types returns a reference to its first element if there are no other, else it returns None.

If this were done with slices, that would require choosing a particular value type of the underlying slice e.g. [String].

Required Methods

fn get_unique(&self) -> Option<&str>

Borrow the unique value reference.

Implementations on Foreign Types

impl UniqueValue for str

fn get_unique(&self) -> Option<&str>

impl UniqueValue for String

fn get_unique(&self) -> Option<&str>

impl<'a, V> UniqueValue for &'a V

where V: AsRef<str> + ?Sized,

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue + ?Sized> UniqueValue for Box<V>

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue + ?Sized> UniqueValue for Rc<V>

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue + ?Sized> UniqueValue for Arc<V>

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue> UniqueValue for Option<V>

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue> UniqueValue for [V]

fn get_unique(&self) -> Option<&str>

impl<V: UniqueValue> UniqueValue for Vec<V>

fn get_unique(&self) -> Option<&str>

Implementors

impl<'a> UniqueValue for Cow<'a, str>