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# holoscan::Nullable

```cpp showLineNumbers={false}
template <typename T>
class Nullable
```

```cpp showLineNumbers={false}
#include <holoscan/nullable_pointer.hpp>
```

**Template parameters**

**`T`** `typename`

---

---

## Constructors

### Nullable \[#nullable]

#### Overload 1

```cpp showLineNumbers={false}
holoscan::Nullable<T>::Nullable(
    T value = 0
)
```

#### From nullptr

```cpp showLineNumbers={false}
holoscan::Nullable<T>::Nullable(
    std::nullptr_t
)
```

---

## Methods

### operator T \[#operatort]

```cpp showLineNumbers={false}
holoscan::Nullable<T>::operator T() const
```

### operator bool \[#operatorbool]

```cpp showLineNumbers={false}
holoscan::Nullable<T>::operator bool()
```

---

## Member variables

| Name     | Type | Description |
| -------- | ---- | ----------- |
| `value_` | `T`  |             |

---

## Inner classes

### Deleter

```cpp showLineNumbers={false}
struct holoscan::Nullable::Deleter
```

[Deleter](#deleter), call the function when the object is deleted.