Tests whether an optional_ref holds a value.
Declared in <absl/types/optional_ref.h>
template<typename T>
constexpr
bool
operator!=(
std::nullopt_t a,
optional_ref<T> b);true if b holds a value.
| Name | Description |
|---|---|
| a | The std::nullopt tag. |
| b | The reference to test. |