 |
C++Talk.NET
C++ language newsgroups
|
| View previous topic :: View next topic |
| Author |
Message |
Harry
Guest
|
 Posted: Mon Nov 28, 2005 7:52 am Post subject: Overload operator << question. |
 |
|
Hi all,
I am writing a logger program which can take any datatype.
namespace recordLog {
enum Debug_Level {low, midium, high};
class L {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
L(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=log_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::out|std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
lstrm, const T& t);
friend std::ostream& operator << (L& lstrm,const Debug_Level&
l);
~L(){os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__;}
};
L& initL(std::string str)
{
//static L ls(str,high);
int dl=atoi(d_level.c_str());
static L ls(str,static_cast
return ls;
}
/*
template<typename T> std::ostream& operator << (L& lstrm, const T&
t)
{
if(lstrm.cdl <= lstrm.ddl)
lstrm.os << t;
return lstrm.os;
}
*/
std::ostream& operator << (L& lstrm,const Debug_Level& l)
{
std::cout<<"I AM LOG"<
lstrm.cdl = l;
return lstrm.os;
}
class E {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
E(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=error_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
const T& t);
friend std::ostream& operator << (E& lstrm,const Debug_Level&
l);
~E(){ os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__; }
};
E& initE(std::string str)
{
static E ls(str,high);
return ls;
}
/*
template
t)
{
std::cout<
lstrm.os << t;
return lstrm.os;
}
*/
std::ostream& operator << (E& lstrm,const Debug_Level& l)
{
lstrm.cdl = l;
return lstrm.os;
}
}
int main()
{
using namespace recordLog;
L& l=initL("harilogger.txt");
E& elog=initE("errorlog.txt");
l<< high <<"test" << 45;
elog<
}
My question is still I commented out the template part..
My program is still writing to the files harilogger.txt and
errorlog.txt.My program will be such as that I will set a debug level
based on which data's will be displayed.
if(lstrm.cdl <= lstrm.ddl)
lstrm.os << t;
if current debug level is less then or equal to desired debug level it
should write the data else it should not.
elog<
Here first I am setting the debug level i,e low and based on which data
<<"Error in this line"<<56;
will be written..
Thanks in advance..
Cheer's
HPS
|
|
| Back to top |
|
 |
Hans Lohninger
Guest
|
| Posted: Mon Nov 28, 2005 8:33 am Post subject: Re: Overload operator << question. |
|
|
More information on operator overloading and the << operator can be found
here:
http://www.vias.org/cppcourse/chap15_08.html
This would not solve your specific problem but gives a good introduction to
that topic.
Regards, Hans
|
|
| Back to top |
|
|
sods
Guest
|
| Posted: Thu Dec 01, 2005 3:58 am Post subject: Re: Overload operator << question. |
|
|
"Harry" <harimcajec (AT) gmail (DOT) com> дÈëÓʼþ
news:1133164371.423403.34660 (AT) f14g2000cwb (DOT) googlegroups.com...
| Quote: | Hi all,
I am writing a logger program which can take any datatype.
namespace recordLog {
enum Debug_Level {low, midium, high};
class L {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
L(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=log_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::out|std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
lstrm, const T& t);
friend std::ostream& operator << (L& lstrm,const Debug_Level&
l);
~L(){os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__;}
};
L& initL(std::string str)
{
//static L ls(str,high);
int dl=atoi(d_level.c_str());
static L ls(str,static_cast
return ls;
}
/*
template<typename T> std::ostream& operator << (L& lstrm, const T&
t)
{
if(lstrm.cdl <= lstrm.ddl)
lstrm.os << t;
return lstrm.os;
}
*/
std::ostream& operator << (L& lstrm,const Debug_Level& l)
{
std::cout<<"I AM LOG"<
lstrm.cdl = l;
return lstrm.os;
}
class E {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
E(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=error_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
const T& t);
friend std::ostream& operator << (E& lstrm,const Debug_Level&
l);
~E(){ os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__; }
};
E& initE(std::string str)
{
static E ls(str,high);
return ls;
}
/*
template
t)
{
std::cout<
lstrm.os << t;
return lstrm.os;
}
*/
std::ostream& operator << (E& lstrm,const Debug_Level& l)
{
lstrm.cdl = l;
return lstrm.os;
}
}
int main()
{
using namespace recordLog;
L& l=initL("harilogger.txt");
E& elog=initE("errorlog.txt");
l<< high <<"test" << 45;
elog<
}
My question is still I commented out the template part..
My program is still writing to the files harilogger.txt and
errorlog.txt.My program will be such as that I will set a debug level
based on which data's will be displayed.
if(lstrm.cdl <= lstrm.ddl)
lstrm.os << t;
if current debug level is less then or equal to desired debug level it
should write the data else it should not.
elog<
Here first I am setting the debug level i,e low and based on which data
"Error in this line"<<56;
will be written..
Thanks in advance..
Cheer's
HPS
|
Hi,
I think the key is the operator <<.
l << high , call your overloaded method,
std::ostream& operator << (L& lstrm,const Debug_Level& l);
but the following << "test" is really call
std::ostream& operator<< (ostream& os, const char * s), isn't it.
so though you commented out your method "template
operator << (L& lstrm, const T& t)",
it's nothing.
maybe you need overload L& operator << (L& lstrm,const const T& l) instead.
try this.
#include
#include <fstream>
#include <string>
namespace recordLog {
enum Debug_Level {low, midium, high};
std::string log_path = "E:\";
std::string error_path = "E:\";
class L {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
L(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=log_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::out|std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
lstrm, const T& t);
friend L& operator << (L& lstrm,const Debug_Level&
l);
~L(){os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__<<"n";}
};
L& initL(std::string str, Debug_Level dl)
{
//static L ls(str,high);
//int dl=atoi(d_level.c_str());
static L ls(str, dl);
return ls;
}
template
t)
{
if(lstrm.cdl <= lstrm.ddl)
lstrm.os << t;
return lstrm;
}
L& operator << (L& lstrm,const Debug_Level& l)
{
std::cout<<"I AM LOG"<
lstrm.cdl = l;
return lstrm;
}
class E {
std::ofstream os;
Debug_Level cdl;
const Debug_Level ddl;
public:
E(std::string filename, const Debug_Level& desired)
: ddl(desired)
{
std::string fname=error_path+filename;
if(!os)
exit(EXIT_FAILURE);
os.open(fname.c_str(),std::ios::app);
os<<"START TIME :" <<__DATE__<<" "<<__TIME__<<"n";
}
template
const T& t);
friend std::ostream& operator << (E& lstrm,const Debug_Level&
l);
~E(){ os<<"nnEND TIME :"<<__DATE__<<" "<< __TIME__<<"n"; }
};
E& initE(std::string str)
{
static E ls(str,high);
return ls;
}
/*
template
t)
{
std::cout<
lstrm.os << t;
return lstrm.os;
}
*/
std::ostream& operator << (E& lstrm,const Debug_Level& l)
{
lstrm.cdl = l;
return lstrm.os;
}
}
int main()
{
using namespace recordLog;
L& l=initL("harilogger.txt", recordLog::low);
// E& elog=initE("errorlog.txt");
l<< high <<"test" << 45;
// elog<
}
sods.
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
