# `@sizeof`
`@sizeof` is helper for accessing the expression provided
for labels defined in a [`@struct`](./struct.md). Normally,
when you have a struct like this:
```
@struct MyStruct
field: 2
@endstruct
```
You have no way to access the result of the expression after
`field`. This size [*"metadata"*](./meta.md) is stored in the
symbol table, but you cannot access it directly. The label
`MyStruct.field` afterall is set to `0`: the offset of the
label from the start of the struct.
To access it easily, use `@sizeof`:
```
@defn FIELD_SIZE, @sizeof MyStruct.field
```
`@sizeof MyStruct.field` in this example will return `2`.
This has nearly the same effect as the much more clunky:
```
@defn FIELD_SIZE, @parse @string { @getmeta MyStruct.field, "@SIZEOF" "\\" }
```
Though `@sizeof` **acts as a unary operator in expressions**. It will be lazily
evaluated if necessary.