[RESOLVED] A simple vmString class

[2kaud]

Why not just use the standard c++ string class? http://www.cplusplus.com/reference/string/

You don't forward declare ostream. ostream is part of the namespace std so

friend std::ostream &operator<<(std::ostream &output, const vmString &str);

and other places where you use ostream.

You need to define the overloaded operator << within the vmStd namespace.

This code compiles and produces the expected output

#include <iostream>
#include <cstring>
#include <cassert>

namespace vmStd {

	class vmString {
		friend std::ostream &operator<<(std::ostream &output, const vmString &str);

	public:
		vmString(const char *str = "");
		vmString(const vmString &cpy);
		~vmString();

		int length() const { return m_nLength; }

	private:
		void AllocString(const char *str);

		int m_nLength;
		char *m_pchStr;  // error: char* vmStd::vmString::m_pchStr' is private
	};

} // namespace vmStd

using namespace vmStd;

//-----------------------------------------------------------------------------
// FN/Method:     vmString(const char * = "")
// Description:   vmString class constructor. Converts char * to a vmString
//                object.
//-----------------------------------------------------------------------------
vmString::vmString(const char *str) : m_nLength(strlen(str)), m_pchStr(0)
{
	AllocString(str);
}

//-----------------------------------------------------------------------------
// FN/Method:     vmString(const vmString &)
// Description:   vmString class copy constructor
//-----------------------------------------------------------------------------
vmString::vmString(const vmString& cpy) : m_nLength(cpy.m_nLength)
{
	AllocString(cpy.m_pchStr);
}

//-----------------------------------------------------------------------------
// FN/Method:     ~vmString()
// Description:   vmString class destructor
//-----------------------------------------------------------------------------
vmString::~vmString()
{
	delete[] m_pchStr;
}

//-----------------------------------------------------------------------------
// FN/Method:     AllocString(const char *)
// Description:   Dynamically allocate memory for new vmString object
//-----------------------------------------------------------------------------
void vmString::AllocString(const char *str)
{
	m_pchStr = new char[m_nLength + 1];  // Allocate storage
	assert(m_pchStr != 0);               // Terminate if memory not allocated
	strcpy(m_pchStr, str);               // Copy literal to vmString object
}

//-----------------------------------------------------------------------------
// FN/Method:     ostream &operator<<(ostream &, const vmString &)
// Description:   Allow the output of a vmString object
//-----------------------------------------------------------------------------
namespace vmStd {
	std::ostream &operator<<(std::ostream &output, const vmStd::vmString &str)
	{
		output << str.m_pchStr;  // error: within this context ???

		return output;  // Enables cascading
	}
}

int main()
{
using namespace vmStd;

	// One part construction
	vmString testStr = "Hello string";
	std::cout << testStr << std::endl;

	return 0;
}