Question

Below is the compilation errors I’m getting and the header/cpp files that go with em. If anyone has a few minutes and a better eye at catching something that I can’t, I would love them forever. This goes back to an a3main.cpp to be tested, so if you need that file fir reference as well just give me a shout. Thanks again!

a3.cpp: In constructor 'disk::disk(int, const char*)': 
a3.cpp:12: error: invalid conversion from 'const char*' to 'char*' 
a3.cpp:12: error:   initializing argument 1 of 'char* strcpy(char*, const char*)' 
a3.cpp: In member function 'void disk::memory(int)': 
a3.cpp:26: error: expected unqualified-id before '=' token 
a3.cpp:28: error: expected primary-expression before '==' token 
a3.cpp: At global scope: 
a3.cpp:37: error: expected initializer before 'mode' 
a3.cpp:42: error: expected initializer before '*' token 
a3.cpp:47: error: expected initializer before 'get_segment'

---

//a3.cpp
#include <iostream>
#include "disk.h"
#include <iomanip>
#include <cstring>
#include <stdlib.h>
using namespace std;

disk::disk(int num_of_segments, const char* mode)
{
    memory(num_of_segments);
    if(strcmp(mode, "w") || !strcmp(mode, "a"))
        strcpy(mode, mode);

    else
        strcpy(mod, "w");
}   

disk::disk()
{
    memory(20);
    strcpy(mod, "w");
}

void disk::memory(int num)          //private, see header file
{
    segment = new segment[num];
// (nothrow) - page 80 in the text
    if(segment == NULL)
    {
        cerr << "Could not find any data in class ";
        exit(0);
    }
    total = num;
    count = 0;
}

const char* disk::get mode() const
{
    return mode;
}

segment segment* disk::get_all_segment() const
{
    return sgmt;
}

int disk::segment get_segment(int pos) const
{
    segment temp;
    if(pos > 0 && pos < count)
    {
        temp = segment[pos];
    }
    return temp;
}

int disk::get_segment_count() const
{
    return count;
}

disk disk::operator+=(const segment &r)
{
    if(count < total)
    {
        sgmt[count] = r;
        count++;
    }
    return *this;
}

void disk::operator=(const disk &r)
{
    if(*this != &r)
    {
        if(sgmt != NULL)
            delete[] sgmt;
        memory(r.total);
        for(int i=0; i < r.count; i++)
        {
            sgmt[i] = r.sgmt[i];
        }
        count = r.count;
        strcpy(mod, r.mod);
    }
}   

disk::disk(const disk& copy)            //copy constructor
{
    memory(copy.total);
    for(int i=0; i<copy.count; i++)
    {
        sgmt[i] = copy.sgmt[i];
    }
    count = copy.count;
    strcpy(mod, copy.mod);
}

disk::~disk()
{
    if(*sgmt != NULL)
    {
        delete[] sgmt;
    }
}

//disk.h
#include "segment.h"
#include <iomanip>
#include <cstring> class disk {
    private:
        segment *sgmt;
        char mod[3];
        int count, total;
        void memory(int);
    public:
        disk(int, const char *);
        disk( );
        const char* get_mode( ) const;
        segment get_segment(int) const;
        int get_segment_count( ) const;
        const segment* get_all_segments( ) const;
        int access(const char [ ]);
        disk operator+=(const segment &);
        void operator=(const disk &);
        disk(const disk &);
        ~disk( ); };

//segment.h
class segment
{
    private:
        char data[SIZE][41];
    public:
        void initialize(const char [][2000], int);
        void initialize();
        int match(const char []);
        void sort();
        void get_word(char [], int);
        int set_word(const char [], int);
        int set_char(int, int, char);
        char get_char(int, int);
};

Answer 1

You need to just work through the errors one by one, starting at the top.

The first error is:

a3.cpp:12: error: invalid conversion from 'const char*' to 'char*' 
a3.cpp:12: error:   initializing argument 1 of 'char* strcpy(char*, const char*)'

And the referenced line 12 is:

strcpy(mode, mode);

You declared mode as const char* and the error says strcpy takes char* as its first argument. The error says its invalid to convert const char* to char*. So it should be clear that the error is that you aren’t allowed to pass mode as the first argument to strcpy.

strcpy(mode, mode); makes no sense and is not allowed. mode cannot be modified but strcpy will modify it. Furthermore, you are trying to copy it over itself, which, if it worked, would do nothing.

---

AndreyT is right about these last errors; you have to learn to just go back and re-read the code they point at and see what you did wrong.

segement in segment = new segment[num]; is a type name, in which case you can’t assign to it like this, or get its value like in if(segment == NULL). You probably mean sgmt.

In const char* disk::get mode() const you forgot an underscore.

In segment segment* disk::get_all_segment() const and int disk::segment get_segment(int pos) const you have an extra segments.