---
title: os_block_t
framework: os
role: symbol
role_heading: Type Alias
path: os/os_block_t
---

# os_block_t

A block that takes no arguments and returns no value.

## Declaration

```occ
typedef void (^)(void) os_block_t;
```

## Discussion

Discussion When not building with Objective-C ARC, a block object allocated on or copied to the heap must be released with a release message or the Block_release function. The declaration of a block literal allocates storage on the stack.

## See Also

### Memory

- [os_proc_available_memory](os/os_proc_available_memory.md)
- [os_function_t](os/os_function_t.md)
- [os_release](os/os_release-c.func.md)
- [os_retain](os/os_retain-c.func.md)