Returns a copy of the wrapped value, promoted as +value_ would promote T.
+value_
T
Declared in <mp-units/utility/safe_int.h>
<mp-units/utility/safe_int.h>
[[nodiscard]] constexpr safe_int<decltype(+value_), ErrorPolicy> operator+() const;
the (possibly promoted) wrapped value
The return value should not be discarded.