Auto Mapper

mapping.cs

Mapper.Initialize(cfg => {
	cfg.CreateMap<account_roles, RoleDTO>()
		.ForMember(x => x.id, opt => opt.MapFrom(x => x.role_id))
		.ForMember(x => x.name, opt => opt.MapFrom(x => x.role_name))
	;

	cfg.CreateMap<account_users, UserDTO>()
		.ForMember(x => x.id, opt => opt.MapFrom(x => x.user_id))
		.ForMember(x => x.email, opt => opt.MapFrom(x => x.user_email))
	;
});

public RoleDTO[] roles()
{
	account_roles[] roles = ae.account_roles.ToArray();

	RoleDTO[] r = new RoleDTO[roles.Length];
	for(int i=0; i<roles.Length; ++i)
	{
		r[i] = Mapper.Map<account_roles, RoleDTO>(roles[i]);
	}

	return r;
}

public UserDTO[] users()
{
	account_users[] users = ae.account_users.ToArray();

	UserDTO[] r = new UserDTO[users.Length];
	for (int i = 0; i < users.Length; ++i)
	{
		r[i] = Mapper.Map<account_users, UserDTO>(users[i]);
	}

	return r;
}

// array
UserDTO[] r = Mapper.Map<account_users[], UserDTO[]>(users);

Details here.