int32_t read_var_int32() { return var_int32_u2s(read_var_uint32()); }
void load(Archive& ar, febird::var_int32_t& x, unsigned ver) { x.t = var_int32_u2s(load_var_uint32(ar)); }
int32_t FileStream::read_var_int32() { return var_int32_u2s(read_var_uint32()); }