# bson_append_oid()

## Synopsis

    #define BSON_APPEND_OID(b, key, val) \
       bson_append_oid (b, key, (int) strlen (key), val)

    bool
    bson_append_oid (bson_t *bson,
                     const char *key,
                     int key_length,
                     const bson_oid_t *oid);

## Parameters

- `bson`: A bson_t.

- `key`: An ASCII C string containing the name of the field.

- `key_length`: The length of `key` in bytes, or -1 to determine the length with `strlen()`.

- `oid`: A bson_oid_t.

## Description

The bson_append_oid() function shall append a new element to `bson` of type BSON_TYPE_OID. `oid` MUST be a pointer to a bson_oid_t.

## Returns

Returns `true` if the operation was applied successfully. The function will fail if appending `oid` grows `bson` larger than INT32_MAX.