GLib.Bytes.get_region

### Method

# GLib Bytesget_region

since: 2.70

#### Declaration [src]

    gconstpointer
    g_bytes_get_region (
      GBytes* bytes,
      gsize element_size,
      gsize offset,
      gsize n_elements
    )

#### Description [src]

Gets a pointer to a region in `bytes`.

The region starts at `offset` many bytes from the start of the data and contains `n_elements` many elements of `element_size` size.

`n_elements` may be zero, but `element_size` must always be non-zero. Ideally, `element_size` is a static constant (eg: `sizeof` a struct).

This function does careful bounds checking (including checking for arithmetic overflows) and returns a non-`NULL` pointer if the specified region lies entirely within the `bytes`. If the region is in some way out of range, or if an overflow has occurred, then `NULL` is returned.

Note: it is possible to have a valid zero-size region. In this case, the returned pointer will be equal to the base pointer of the data of `bytes`, plus `offset`. This will be non-`NULL` except for the case where `bytes` itself was a zero-sized region. Since it is unlikely that you will be using this function to check for a zero-sized region in a zero-sized `bytes`, `NULL` effectively always means ‘error’.

Available since: 2.70

#### Parameters

`element_size`

  Type: `gsize`

  A non-zero element size.

`offset`

  Type: `gsize`

  An offset to the start of the region within the `bytes`.

`n_elements`

  Type: `gsize`

  The number of elements in the region.

#### Return value

Type: `gconstpointer`

The requested region, or `NULL` in case of an error.

The returned data is owned by the instance.
The return value can be `NULL`.