SQLite

** for the values it stores.  ^Values stored in sqlite3_value objects
** can be integers, floating point values, strings, BLOBs, or NULL.
**
** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies
** whether or not it requires a protected sqlite3_value.  The
** [sqlite3_value_dup()] interface can be used to construct a new 
** protected sqlite3_value from an unprotected sqlite3_value.
**
** The terms "protected" and "unprotected" refer to whether or not
** a mutex is held.  An internal mutex is held for a protected
** sqlite3_value object but no mutex is held for an unprotected
** sqlite3_value object.  If SQLite is compiled to be single-threaded
** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
** or if SQLite is run in one of reduced mutex modes 

** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
** is a [protected sqlite3_value] object even if the input is not.
** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
** memory allocation fails.
**
** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
** then sqlite3_value_free(V) is a harmless no-op.
*/
SQLITE_EXPERIMENTAL sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
SQLITE_EXPERIMENTAL void sqlite3_value_free(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context

** when it has finished using that result.
** ^If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** ^The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy of the
** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that the [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** ^A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.