How to define class final constants?

[Allen]

I defines FileLogConstant class as following.

class FileLogConstant
{
public:
static const INT32 REGISTER_LOGGER ;

static const INT32 REGISTER_METHOD ;

static const INT32 MAX_LOGGER_COUN T;

static const INT32 MAX_LOGGER_METH OD_COUNT;

static const INT32 MAX_LOG_MESG_CO UNT;

static const INT32 MAX_REG_COUNT;

static const INT32 MAX_FILE_LENGTH ;
};

/////////////////////////////////////////////BLOCK
DEF//////////////////////////////////////////////////////////////

const INT32 FileLogConstant ::REGISTER_LOGG ER = 0x00;

const INT32 FileLogConstant ::REGISTER_METH OD = 0x01;

const INT32 FileLogConstant ::MAX_LOGGER_CO UNT = 64;

const INT32 FileLogConstant ::MAX_LOGGER_ME THOD_COUNT = 128;

const INT32 FileLogConstant ::MAX_LOG_MESG_ COUNT = 128;

const INT32 FileLogConstant ::MAX_REG_COUNT = 16;

const INT32 FileLogConstant ::MAX_FILE_LENG TH = 4 + 4 +
FileLogConstant ::MAX_LOGGER_CO UNT *
(16 + 4 + 64 * FileLogConstant ::MAX_LOGGER_ME THOD_COUNT) + 4 + 4 +
FileLogConstant ::MAX_LOG_MESG_ COUNT * (2 + 2 + 4 + 4 + 256) +
FileLogConstant ::MAX_REG_COUNT * (2 + 2 + 64);

/////////////////////////////////////////////////BLOCK
DEF////////////////////////////////////////////////////////////

class Foo
{
public:
char buffer[FileLogConstant ::MAX_FILE_LENG TH];
};

when BLOCK DEF is put in FileLogConstant .cpp file, the buffer
declaration of class Foo will be compiled with an error. While BLOCK
DEF is put in FileLogConstant .h file, the compiler will generate many
const FileLogConstant ::MAX_FILE_LENG TH already defined errors.

How to define class final constants?

[Alf P. Steinbach]

* Allen:

I defines FileLogConstant class as following.

class FileLogConstant
{
public:
static const INT32 REGISTER_LOGGER ;

Don't use all uppercase except for macros (which should all be all
uppercase).

const INT32 FileLogConstant ::REGISTER_LOGG ER = 0x00;

Apart from the all uppercase name (don't) this is technically OK. But I
suspect that you have placed this definition in a file that you include
more than once. If it's included more than once in the same translation
unit then the compiler will complain, and otherwise, if it's included in
more than one translation unit the linker will complain, because you're
then violating the One Definition Rule.

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[Allen]

Thank you.

I want to replace macro constant definitions with class member
constants. But
can these member constants directly used in the array dimension of
class member
declaration? i.e.

class Foo
{
public:
char buffer[ConstantCls::co nstant1];
};

[David Harmon]

On 27 Nov 2006 18:00:23 -0800 in comp.lang.c++, "Allen"
<ch****@naritec h.cnwrote,

>I want to replace macro constant definitions with class member
constants. But
can these member constants directly used in the array dimension of
class member
declaration?

Yes.

[Allen]

"David Harmon дµÀ£º

>
Yes.

Do you have sample codes?
I tried but failed.
The compiler tells two kinds of errors, redefinition and non-static
dimension.

[BobR]

Allen wrote in message ...

/* """
"David Harmon дµÀ£º

>
Yes.

Do you have sample codes?
I tried but failed.
The compiler tells two kinds of errors, redefinition and non-static
dimension.

""" */

class Allen{
static const size_t Max = 5;
public:
Allen();
};

[Allen]

>

class Allen{
static const size_t Max = 5;
public:
Allen();
};

This code cannot be compiled.

What I want is class member constant used directly by array dimension
declaration:

class Allen{
static const size_t Max;
static char buffer[Max]; // Max cannot be used here. I do want.
public:
Allen();
};

[David Harmon]

On 29 Nov 2006 00:16:36 -0800 in comp.lang.c++, "Allen"
<ch****@naritec h.cnwrote,

>What I want is class member constant used directly by array dimension
declaration:

class Allen{
static const size_t Max;

static const size_t Max = 73;

static char buffer[Max]; // Max cannot be used here. I do want.
public:
Allen();
};

[kwikius]

Allen wrote:

class Allen{
static const size_t Max = 5;
public:
Allen();
};

This code cannot be compiled.

? It should compile OK AFAICS :

#include <iostream>

// static integral constants can be initialised inline:
class Allen{
static const size_t Max = 5; //fine
public:
Allen(){}
};

class Allen1{
static const size_t Max = 5; //fine

public:
static char buffer[Max]; // declaration fine
Allen1(){}
};

char Allen1::buffer[] = "fine"; // member definition in cpp file

int main()
{
std::cout << Allen1::buffer <<'\n';
}

regards
Andy Little

[Allen]

No. It cannot be compiled by VC++ 6.0.
I will test with gcc.

"kwikius дµÀ£º
"

Allen wrote:

>
class Allen{
static const size_t Max = 5;
public:
Allen();
};

This code cannot be compiled.

? It should compile OK AFAICS :

#include <iostream>

// static integral constants can be initialised inline:
class Allen{
static const size_t Max = 5; //fine
public:
Allen(){}
};

class Allen1{
static const size_t Max = 5; //fine

public:
static char buffer[Max]; // declaration fine
Allen1(){}
};

char Allen1::buffer[] = "fine"; // member definition in cpp file

int main()
{
std::cout << Allen1::buffer <<'\n';
}

regards
Andy Little