// STL10.cp
#include <string>

int main()
{
	std::string	a = "shared string";
	std::string	b(a);			// a and b are sharing the same string buffer

	if (a[0] != b[0])					// line 1
	{
		a = b = "un" + a;				// line 2
	}
	if (a.c_str()[0] == b.c_str()[0])	// line 3
	{
		a = b = "un" + a;				// line 4
	}
	// a and b are no longer sharing the same string buffer
	// Question: At what line is the buffer copied?
}