# `value_type &value() &`

Wide contract lvalue reference observer of any value present. `NoValuePolicy::wide_value_check()` is first invoked, then the reference to the value is returned.

Note that if `value_type` is `void`, only a `const` overload returning `void` is present.

Requires: Always available.

Complexity: Depends on `NoValuePolicy::wide_value_check()`.

Guarantees: None.

Last revised: February 12, 2019 at 16:36:24 UTC