This is a convenience function for using a glib.HashTable as a set. It is equivalent to calling HashTable.replace with key as both the key and the value.

In particular, this means that if key already exists in the hash table, then the old copy of key in the hash table is freed and key replaces it in the table.

When a hash table only ever contains keys that have themselves as the corresponding value it is able to be stored more efficiently. See the discussion in the section description.

Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.

class HashTable
void* key


key void*

a key to insert

Return Value

Type: bool

TRUE if the key did not exist yet