lock_value

Make the value under a given key immutable.

Synopsis

lock_value(%hash, $key);

Any subsequent attempt to overwrite $hash{$key} croaks with Modification of a read-only value attempted. The key itself remains deletable unless lock_keys has also been applied — once the key is deleted, a later assignment creates a fresh (writable) value. Values not already present are silently ignored.

Returns a reference to the hash.