Undefined reference to 'operator delete(void*)'

Question

I\'m new to C++ programming, but have been working in C and Java for a long time. I\'m trying to do an interface-like hierarchy in some serial protocol I\'m working on, and kee

Answer 1

If you're just looking to do an interface, you don't need new/delete. Just remove the "virtual" from the base class destructor, and make sure the derived class has an implementation of __cxa_pure_virtual().

Here is a compilable example. (I removed the returns to keep things simple, but it works just fine with them.)

In PacketWriter.h

class PacketWriter {
public:
    virtual void nextByte() = 0;
protected:
    ~PacketWriter() {}
};

In StringWriter.h

#include "PacketWriter.h"

class StringWriter : public PacketWriter {
public:
    StringWriter(const char* message);
    void nextByte();
};  

In StringWriter.cpp

#include "StringWriter.h"

// Definition of the error function to call if the constructor goes bonkers
extern "C" void __cxa_pure_virtual() { while (1); }

StringWriter::StringWriter(const char* message)
{
    // constructor code here
}

void StringWriter::nextByte()
{
}

Compile with avr-g++ StringWriter.cpp