Method

GLibBytesget_region

Declaration

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

Description

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 gsize
 

A non-zero element size.

offset gsize
 

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

n_elements gsize
 

The number of elements in the region.

Return value

Returns: gpointer
 

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