topic Re: Problems with fstream( ) in Classic/Legacy CodeWarrior

Problems with fstream( )

mama — Mon, 22 Jun 2009 22:56:17 GMT

These days I've started to check out a few things about the C++ support of the CodeWarrior (V. 5.7.1844). I created a small C++ Project and I tried to get the following to run:

#include <iostream>
#include <fstream.h>

using namespace std;

void readFile()
{
fstream inOut("test.txt", ios::in | ios:ut);

}

I always get the Compile Error message: "Error: too many initializers"

If I remove the openemode flags it normally should compile,too , because there is a default parameter in the constructor, but this:

fstream inOut("text.txt");

delivers the compile error:

"Error: implicit conversion from 'const char[9]' to 'std::basic_fstream<char, std::char_traits<char>>'

I have checked all the target settings and the include file contents, but i cannot find a solution to solve the compile errors.

Has anybody an idea ?

Thanks in Advance

mama

Re: Problems with fstream( )

CompilerGuru — Tue, 23 Jun 2009 00:45:14 GMT

use #include <fstream> and not the pre-ansi #include <fstream.h>.

According to

http://www2.roguewave.com/support/docs/leif/sourcepro/html/stdlibref/basic-fstream.html

The constructor you are trying to use is explicit, so you have to call it explicitely.

Without having it tried:

fstream inOut = fstream("text.txt");

Daniel

Re: Problems with fstream( )

mama — Tue, 23 Jun 2009 14:56:49 GMT

Hello Daniel,

thanks for your quick answer and sorry for my stupid typing error about the fstream.h extension. Yes of course, I have included it this way in my test programm: #include<fstream> (next time I better do copy and paste), but it does not change the compile error message. Here I have another code snippet below where I tried to get it compilable, but I am not able to solve the problem. You're suggestion about the constructor call delivers another compile error ?

I will be very thankful for advises.

Thanks Marc

// fstream is just forwarded to basic_fstream in file "iosfwd"

template <class charT, class traits = char_traits<charT> >
class basic_fstream;

typedef basic_fstream<char, char_traits<char> > fstream;

// The called constructor basic_fstream in file "fstream"
explicit basic_fstream(const char* s,

ios_base:penmode mode = ios_base::in | ios_base:ut);

---------------------------------------------------------------------------------------------

#include <iostream>
#include <fstream>

#include "test.h"

using namespace std;

void readFile()
{
// Error   : too many initializers
//             test.cpp line 14    fstream inOut("test.txt", ios::in | ios:ut);
  fstream inOut("test.txt", ios::in | ios:ut);

// Error   : illegal use of incomplete struct/union/class
//             'std::basic_fstream<char, std::char_traits<char>>'
//              test.cpp line 18    fstream inOut2 = fstream("test.txt");
fstream inOut2 = fstream("test.txt");

// Error : illegal use of incomplete struct/union/class

//            'std::basic_fstream<char, std::char_traits<char>>'
//            test.cpp line 22    fstream inOut3 = fstream("test.txt", ios::in | ios:ut);
fstream inOut3 = fstream("test.txt", ios::in | ios:ut);

const char c[] = "text.txt";
ios_base:penmode mode = ios_base::in | ios_base:ut;
// Error   : template argument list expected
//             test.cpp line 35   explicit basic_fstream(const char* s,
//                                     ios_base:penmode mode = ios_base::in | ios_base:ut);
fstream inOut4 = fstream(c, mode);

}

Re: Problems with fstream( )

mama — Tue, 23 Jun 2009 17:35:10 GMT

Oh what a disaster. Now I found the reason for the compile errors by using fstream( ).

I wondered why it makes no difference if I #include<fstream> or not. The reason is

that the basic_fstream class is commented out by preprocessor define _MSL_NO_FILE_IO

in the include file <fstream>.

So the compiler sees just the following forward declaration.....

// fstream is just forwarded to basic_fstream in file "iosfwd"
template <class charT, class traits = char_traits<charT> >
class basic_fstream;
typedef basic_fstream<char, char_traits<char> > fstream;

.....but the implementation of class basic_fstream is missing.

So I thought no problem...comment out #define _MSL_NO_FILE_IO an it works.

No way, when I comment it out I got other compile error in Metrowerks MSL library:

----------------------

Error : undefined identifier 'fclose'

(point of instantiation: 'readFile()')

(instantiating: 'Metrowerks::c_filebuf<char, std::char_traits<char>>::~c_filebuf()')

(instantiating: 'Metrowerks::c_filebuf<char, std::char_traits<char>>::close()')

msl_c_filebuf line 323 if (_CSTD::fclose(file_) != 0)

(corresponding point of instantiation for 'Metrowerks::c_filebuf<char, std::char_traits<char>>::close()')

msl_c_filebuf line 141 }

(corresponding point of instantiation for 'Metrowerks::c_filebuf<char, std::char_traits<char>>::~c_filebuf()')

test.cpp line 30 }

----------------------

Either the fstream support does not work when using MSL with E68k, or I have to activate/deactivate other precompiler seeting here. Has any body of you experience with this kind of problem.

Thanks in Advance

Marc

P.S. Info from MSL C++ Manual:

_MSL_NO_FILE_IO: This flag allows you to turn off file support while keeping memory mapped streams (stringstream) functional.