Looks like the code formatting got messed up by the elog... here it is in the attachment instead.

#include <iostream>
#include <unistd.h>

void i2c_set_bit(int bit, int val) {
	std::cout << "Bit " << bit << " set to " << val << "\n";
}

class i2c_temp_bit {
	int bit; /* which bit */
	int newval; /* value to set bit to */
	int oldval; /* value to reset bit to */
public:
	i2c_temp_bit(int b, int nv, int ov)
		: bit{b}, newval{nv}, oldval{ov}
	{
		std::cout << "Bit " << bit << " set to " << newval << "\n";
	}
	~i2c_temp_bit() 
	{
		std::cout << "Bit " << bit << " set to " << oldval << "\n";
	}
	i2c_temp_bit(const i2c_temp_bit&) = delete;
	i2c_temp_bit(i2c_temp_bit&&) = delete;
	i2c_temp_bit& operator=(const i2c_temp_bit&) = delete;
	i2c_temp_bit& operator=(i2c_temp_bit&&) = delete;
};

int check_kettle_temp() {
	static int callnum = 0;
	if (++callnum > 5) {
		return 100;
	}
#ifdef BADNUM
	else if (callnum == 4) { /* Don't like this number */
		throw callnum;
	}
#endif
	else {
		return 25;
	}
}

void foo() {
	std::cout << "Waiting for kettle to boil" << std::endl;
	do { /* Check every 100 ms */
		usleep(100000);
	} while (check_kettle_temp() < 100);
	std::cout << "Water is boiled!" << std::endl;
}

void boil_kettle()
{
#ifdef RAII
	i2c_temp_bit temp(10, 1, 0);
	foo();
#else
	i2c_set_bit(10, 1); // bit 10 is stove heater control, turn it on
	foo(); // wait for kettle to start boiling
	i2c_set_bit(10, 0); // turn heater off
#endif
}

int main()
{
	try {
		boil_kettle();
	} catch (...) {
		std::cerr << "Abnormal termination\n";
	}
}