# Annotation Glossary

### A

allow-none

  NULL is OK, both for passing and for returning.

array

  Parameter points to an array of items.

### C

closure

  This parameter is a 'user_data', for callbacks; many bindings can pass NULL here.

### E

element-type

  Generics and defining elements of containers and arrays.

### I

in

  Parameter for input. Default is transfer none.

### N

nullable

  NULL may be passed as the value in, out, in-out; or as a return value.

### O

out

  Parameter for returning results. Default is transfer full.

out caller-allocates

  Out parameter, where caller must allocate storage.

### R

rename-to

  Rename the original symbol's name to SYMBOL.

### S

scope async

  The callback is valid until first called.

scope call

  The callback is valid only during the call to the method.

skip

  Exposed in C code, not necessarily available in other languages.

### T

transfer container

  Free data container after the code is done.

transfer floating

  Alias for transfer none, used for objects with floating refs.

transfer full

  Free data after the code is done.

transfer none

  Don't free data after the code is done.