C++ Error: 'undefined reference to 'GFile::Flush(gfBlockT*)'' - Fix and Explanation

The provided C++ code exhibits an error: 'undefined reference to 'GFile::Flush(gfBlockT*)''. This error arises because the 'Flush' function is called within the 'FlushAll' function, but it's not defined or declared anywhere in the code. To rectify this, you need to provide the definition or declaration of the 'Flush' function.

Assuming 'Flush' is a member function of the 'GFile' class, the corrected code would appear as follows:

class GFile {
public:
    void Flush(gfBlockT*);
    void FlushAll();

private:
    gfBlockT* CurrentBlock;
};

void GFile::Flush(gfBlockT* block) {
    // Implement the Flush function here
}

void GFile::FlushAll() {
    Flush(CurrentBlock);
}

It is essential to replace the '// Implement the Flush function here' comment with the actual implementation of the 'Flush' function based on your specific requirements. This implementation should define the functionality of the 'Flush' function, which is likely related to writing data to a file or other output stream.

By providing a proper definition or declaration of the 'Flush' function within the 'GFile' class, the 'undefined reference' error will be resolved, allowing the code to compile and execute correctly.