# `structure`

A Structure is a dynamic byteclass created using the `@structure` decorator.

```python
@structure
class MyStructure:
    """My Structure Byteclass."""

    var1: UInt64
    var2: UInt32
```

Similar to a C `struct`, each member of a byteclass `structure` has a sequential offset. By default, `structure` are padded so each member is size aligned. The `structure` decorator accepts a boolean `padding` parameter to override the default padding behavior.

The length of a Structure byteclass is determined when the class is created based on its members.

A Structure byteclass can contain both byteclass primitives and other byteclass collections.

Each Structure member has its own `byte_order`. However, the `structure` decorator accepts a `byte_order` parameter which is used for any members that rely on a `factory` for instantiation.

> If no member value is specified, the member type annotation is used as a `factory`.

```python
@structure(byte_order=b"@")
class Structure1:
    """A structure byteclass with one member using default factory."""

    a: UInt64 = member(factory=UInt64)

@structure
class Structure2:
    """A structure byteclass with one member using default factory."""

    a: UInt64
```

The `Structure1` and `Structure2` defined above are functionally equivalent.