ps_immutable
_PROP_ASSERT(ps1->ps_immutable != NULL);
_PROP_ASSERT(ps2->ps_immutable != NULL);
return strcmp(ps1->ps_immutable, ps2->ps_immutable);
_PROP_ASSERT(ps->ps_immutable != NULL);
return strcmp(ps->ps_immutable, cp);
ps->ps_immutable);
ps->ps_immutable = str;
return (ps->ps_immutable);
#define prop_string_contents(x) ((x)->ps_immutable ? (x)->ps_immutable : "")