Classes in other header files?

Question

I have a class in another .h and .cpp file from my main.cpp.

In main.cpp:

#include <iostream>
#include "filestuff.h"
#include "stream.h" <-- right here

int main(int argc, char** args)
{
    if(!args[1])
        return 0;

    u64 filesize = 0;
    get_file_size(args[1], &filesize);
    u8* fd = new u8[filesize];
    read_file(args[1], fd, filesize);

    Stream s = new Stream(fd, filesize, "rb", BigEndian );

    getchar();
    return 0;
}

In Stream.h

#include <iostream> //just in case?

#if defined(_WIN32) && defined(_MSC_VER)
    typedef __int64 s64;
    typedef unsigned __int64 u64;
#else
    typedef long long int s64;
    typedef unsigned long long int u64;
#endif

typedef unsigned long int u32;
typedef signed long int s32;
typedef unsigned short int u16;
typedef signed short int s16;
typedef unsigned char u8;
typedef signed char s8;

#define LittleEndian 0x1
#define BigEndian 0x2

class Stream
{
public:
    Stream(u8* buffer, u64 length, char* access, int IOType);
private:
    u8* buffer;
    u64 pos;
    u64 len;
};

In Stream.cpp

#include "stream.h"

Stream::Stream(u8* buffer, u64 length, char* access, int IOType)
{
    u8* buf = new u8[length];
    buffer = buf;
}

How can I use the following code to initialize my class like I want to do in main now?

Stream* s = new Stream(fd, filesize, "rb", BigEndian );

Yeah @alexbuisson Stream* doesn't work either. I just removed to see if it would fix — MysteryDev, Jul 23 '13 at 06:30
"How can I use the following code" - you can't. It's broken. So is `Stream::Stream`, since repointing the `buffer` argument won't affect the caller, and you're not freeing memory anywhere. You should be asking what you *should* be doing, not "how do I make the answer I'm using be the right answer". — user2357112, Jul 23 '13 at 06:31
Post any error messages you're seeing and, if possible, how the compiler is invoked. I suspect you're not compiling Stream.cpp or not linking main.o with Stream.o. — arne, Jul 23 '13 at 06:32
@user2357112 can you help? i've only done basic file IO in C++ and math and w/e — MysteryDev, Jul 23 '13 at 06:32
Also please use [](http://en.cppreference.com/w/cpp/header/cstdint). — Jesse Good, Jul 23 '13 at 06:33
This question appears to be off-topic because it is about typo in your code — Tadeusz Kopec for Ukraine, Jul 23 '13 at 06:46
@Jakes625 You don't need to correct the code in your question - that will make the answers obsolete and will make it harder for future readers to understand if they face similar issues. — default, Jul 23 '13 at 06:47

score 6 · Answer 1 · answered Jul 23 '13 at 06:32

6

Real error is in #define LittleEndian = 0x1. Remove =.

answered Jul 23 '13 at 06:32

cahn

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ahh gets me everytime! – MysteryDev Jul 23 '13 at 06:34
Real solution: use `static const int LittleEndian = 0x1;` – MatthewD Jul 23 '13 at 06:38

score 2 · Accepted Answer · edited May 23 '17 at 11:57

2

You have an error here :

Stream *s = new Stream(fd, filesize, "rb", BigEndian );
//     ^

The operator new return a pointer to the newly allocated storage space. So s has to be a pointer to get it working.

And you should have a destructor. You are allocating dynamic memory with new[], you should free it before leaving :

Stream::~Stream()
{
    if ( NULL != buffer )
    {
        delete [] buffer;
    }
}

And when you don't need s anymore :

delete s;

Last error :

#define LittleEndian = 0x1
//                   ^

Remove the =.

And in C++, it is a better practice to use static const variable :

static const int LittleEndian = 0x1;

Look at this : static const vs #define

EDIT : For the constructor :

Stream::Stream(u64 iLength, char* iAccess, int iIOType):
    mBuffer( new u8[iLength] )
{
}

// With mBuffer member of the Stream class.

edited May 23 '17 at 11:57

Community

1
1

answered Jul 23 '13 at 06:30

Pierre Fourgeaud

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better yet I could probably do if(buffer){ buff = new u8[len]; buffer = buff; } – MysteryDev Jul 23 '13 at 06:38
I suggest to rename the arguments in your constructor or you members in your class, it is a bit confusing... Look at the edit. – Pierre Fourgeaud Jul 23 '13 at 06:41
1

the `~` is the caractere for the destructor. It is the method who is called at the destruction of the object. You should read this : http://www.cplusplus.com/doc/tutorial/classes/ – Pierre Fourgeaud Jul 23 '13 at 06:45

score 0 · Answer 3 · answered Jul 23 '13 at 06:32

0

There are two probable mistakes. If you want a pointer to an object, write

Stream *s = new Stream(fd, filesize, "rb", BigEndian );

And if you want an object itself and not a pointer, write

Stream s(fd, filesize, "rb", BigEndian );

answered Jul 23 '13 at 06:32

Ivan Smirnov

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score 0 · Answer 4 · answered Jul 23 '13 at 06:34

in your main if you use dynamic allocation you must replace

     Stream s = new Stream(fd, filesize, "rb", BigEndian );

by

      Stream* s = new Stream(fd, filesize, "rb", BigEndian );

so s become a pointer on a Stream object. all call to function of the stream class should be done with : s-> or (*s).

and don't forget to remove your memory with

 delete s;

score 0 · Answer 5 · answered Jul 23 '13 at 06:39

0

Plenty of errors pointed out so far. Here's another: In your constructor, you set

buffer = buf

That doesn't actually assign to the Stream's buffer member. That assigns to the constructor's buffer argument. You most likely want

this->buffer = buf

That said, I'm not really sure why you take a buffer as an argument, only to allocate a different one. Maybe it'll make sense when you finish your code.

answered Jul 23 '13 at 06:39

user2357112

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no you're right, I noticed that after I posted it. It's 1:40 AM. I really should have attempted this during day time. :/ – MysteryDev Jul 23 '13 at 06:40

Classes in other header files?

5 Answers5