What am I doing worng?

I have been reading C++ Primer Plus, and I'm stuck on this programming question:

Begin with the following structure declaration:
struct chaff
{
char dross[20];
int slag;
};
Write a program that uses placement new to place an array of two such structures in a
buffer. Then assign values to the structure members (remembering to use strcpy() for
the char array) and use a loop to display the contents. Option 1 is to use a static array,
like that in Listing 9.9, for the buffer. Option 2 is to use regular new to allocate the
buffer.

This is what I have:

Code:

#include <iostream>
#include <new>

using namespace std;

struct chaff
{
	char dross[20];
	int slag;
};

int main()
{
	char * buf = new char(sizeof(chaff) * 2);
	chaff * c1 = new (buf) chaff;
	chaff * c2 = new (buf + sizeof(chaff)) chaff;
	strcpy(c1->dross, "Chaff 1");
	c1->slag = 5;
	strcpy(c2->dross, "Chaff 2");
	c2->slag = 2;
	chaff * c;
	for (int i = 0; i < 2; i++)
	{
		c = (chaff *) &buf[sizeof(chaff) * i];
		cout << c->dross << endl;
		cout << c->slag << endl;
	}
	delete [] buf;
}

It compiles, but when I run it I get this

First-chance exception at 0x7c91916a in book samples.exe: 0xC0000005: Access violation reading location 0x0037a8ed.
First-chance exception at 0x7c812afb in book samples.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x0012fc44..
Unhandled exception at 0x7c812afb in book samples.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x0012fc44..
The program '[3552] book samples.exe: Native' has exited with code 0 (0x0).

You got some syntax issues with your use of new. One possible way to handle that part:

Code:

	char * buf = new char[sizeof(chaff) * 2];
	chaff * c1 = new (buf) chaff[2];

So c1 points to two chaff objects... no need for a c2 var.

Code:

chaff * c;
for(...)
{
    c = (chaff *) &buf[sizeof(chaff) * i];

This part could be much simpler:

Code:

chaff * c;
for(...)
{
    c = c1+i;