package capnp

storage_t is the type of the underlying storage associated with this segment (e.g. "bytes").

'cap t is the type of a message. The 'cap annotation is type ro for read-only segments, and type rw for read/write segments.

create size allocates a new zero-filled single-segment message of at least size bytes, raising an exception if storage cannot be allocated.

release m immediately releases the storage for all segments of message m, potentially making the storage available for future allocations. After releasing a storage segment, the behavior of the accessor functions is undefined.

num_segments m obtains the number of segments associated with message m.

total_size m gets the total size of the message, in bytes, across all segments.

total_alloc_size m gets total size of the underlying storage for the message, in bytes, across all segments. (This is at least as large as the value returned by total_size.

get_segment m i gets zero-indexed segment i associated with message m.

• raises Invalid_argument

  if the index is out of bounds.

readonly m obtains a view of message m which is read-only qualified.

of_storage chunks constructs a read/write message which uses the list of storage chunks as the underlying storage media for the message segments.

to_storage m retrieves a list of the storage elements associated with the message segments.

with_message m ~f first evaluates f m, then invokes release m, then returns the result of the application of f. If f m raises an exception, the exception will be propagated after a call to release.

with_attachments attachments m is a message sharing the same storage as m, but with the given attachments. If m is mutable, it should not be used after calling this. Effectively, attachments is a constructor argument, but it isn't known until slightly after the message is constructed.

get_attachments m returns the handler previously set in with_attachments, or No_attachments if no attachments were given.