freeze()
public
Prevents further modifications to obj. A RuntimeError will be raised if modification
is attempted. There is no way to unfreeze a frozen object. See also
Object#frozen?.
This method returns self.
a = [ "a", "b", "c" ]
a.freeze
a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen array (RuntimeError)
from prog.rb:3
Show source
VALUE
rb_obj_freeze(VALUE obj)
{
if (!OBJ_FROZEN(obj)) {
if (rb_safe_level() >= 4 && !OBJ_UNTRUSTED(obj)) {
rb_raise(rb_eSecurityError, "Insecure: can't freeze object");
}
OBJ_FREEZE(obj);
if (SPECIAL_CONST_P(obj)) {
if (!immediate_frozen_tbl) {
immediate_frozen_tbl = st_init_numtable();
}
st_insert(immediate_frozen_tbl, obj, (st_data_t)Qtrue);
}
}
return obj;
}