{

int balance_;

void Deposit(int amount)

{

balance_ += amount;

}

void Withdraw(int amount)

{

balance_ -= amount;

}

int GetBalance()

{

return balance_;

}

{

typedef basic_lockable_adapter<mutex> lockable_base_type;

AccountManager() :

lockable_base_type(), checkingAcct_(*this), savingsAcct_(*this)

{

}

inline void Checking2Savings(int amount);

inline void AMoreComplicatedChecking2Savings(int amount);

/*<-*/

bool some_condition()

{

return true;

} /*->*/

externally_locked<BankAccount, AccountManager > checkingAcct_;

externally_locked<BankAccount, AccountManager > savingsAcct_;

{

strict_lock<AccountManager> guard(*this);

checkingAcct_.get(guard).Withdraw(amount);

savingsAcct_.get(guard).Deposit(amount);

unique_lock<AccountManager> guard1(*this);

if (some_condition()) {

guard1.lock();

}

{

nested_strict_lock<unique_lock<AccountManager> > guard(guard1);

checkingAcct_.get(guard).Withdraw(amount);

savingsAcct_.get(guard).Deposit(amount);

}

guard1.unlock();

{

AccountManager mgr;

mgr.Checking2Savings(100);

return 0;