code syntax

[Gary Wessle]

the code below is a close parallel to the code which is generating an
error I am trying to fix. the error is refereeing to the line in the
code marked <<<<<<<<<<<<< <.
can you please tell if the code is correct?

thanks

#include <string>
using std::string;
#include <vector>
using std::vector;
#include <fstream>
using std::ofstream;

class Ot {
static ofstream combo;
ofstream deta_f;
void some_method();

public:
Ot::Ot(string s){
combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}

void Ot::some_method (){
deta_f << "...";
combo << "...";
}
};

class Grd {
Ot ot;
public:
Grd(string s):ot(s){}
};

class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd); //<<<<<<<<<<<<<<< <<<<<<
}
public:
Grp(){}
~Grp(){}
};

[Mark P]

Re: code syntax

Gary Wessle wrote:

the code below is a close parallel to the code which is generating an
error I am trying to fix. the error is refereeing to the line in the
code marked <<<<<<<<<<<<< <.
can you please tell if the code is correct?

In the future, sharing the error message with the rest of us would be
helpful.

>
thanks
>
#include <string>
using std::string;
#include <vector>
using std::vector;
#include <fstream>
using std::ofstream;
>
class Ot {
static ofstream combo;
ofstream deta_f;
void some_method();
>
public:
Ot::Ot(string s){
combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}
>
void Ot::some_method (){
deta_f << "...";
combo << "...";
}
};
>
class Grd {
Ot ot;
public:
Grd(string s):ot(s){}
};
>
class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd); //<<<<<<<<<<<<<<< <<<<<<

The value type of a vector must be default constructible. Since you've
supplied your own constructor for class Grd the compiler does not
provide you a default constructor.

Mark

}
public:
Grp(){}
~Grp(){}
};

[David Harmon]

Re: code syntax

On 21 Dec 2006 09:30:21 +1100 in comp.lang.c++, Gary Wessle
<phddas@yahoo.c omwrote,

>the code below is a close parallel to the code which is generating an
>error I am trying to fix.

The error is accompanied by a friendly helpful message from the compiler
telling you what is wrong. Read it.

[Gary Wessle]

Re: code syntax

Gary Wessle <phddas@yahoo.c omwrites:

the code below is a close parallel to the code which is generating an
error I am trying to fix. the error is refereeing to the line in the
code marked <<<<<<<<<<<<< <.
can you please tell if the code is correct?
>
thanks
>
#include <string>
using std::string;
#include <vector>
using std::vector;
#include <fstream>
using std::ofstream;
>
class Ot {
static ofstream combo;
ofstream deta_f;
void some_method();
>
public:
Ot::Ot(string s){
combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}
>
void Ot::some_method (){
deta_f << "...";
combo << "...";
}
};
>
class Grd {
Ot ot;
public:
Grd(string s):ot(s){}
};
>
class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd); //<<<<<<<<<<<<<<< <<<<<<
}
public:
Grp(){}
~Grp(){}
};

just some fixes but not compiling still

*************** *************** *************** *************** ****

#include <string>
using std::string;
#include <vector>
using std::vector;
#include <fstream>
using std::ofstream;
using std::ios;

class Ot {
static ofstream combo;
ofstream deta_f;
public:
Ot(string s){
combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}

void some_method(){
deta_f << "...";
combo << "...";
}
};

class Grd {
Ot ot;
public:
Grd(string s):ot(s){}
};

class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd);
}
public:
Grp(){}
~Grp(){}
};
*************** *************** *************** *************** ****

[Bo Yang]

Re: code syntax

Gary Wessle :

Gary Wessle <phddas@yahoo.c omwrites:
>

>the code below is a close parallel to the code which is generating an
>error I am trying to fix. the error is refereeing to the line in the
>code marked <<<<<<<<<<<<< <.
>can you please tell if the code is correct?
>>
>thanks
>>
>#include <string>
>using std::string;
>#include <vector>
>using std::vector;
>#include <fstream>
>using std::ofstream;
>>
>class Ot {
> static ofstream combo;
> ofstream deta_f;
> void some_method();
>>
>public:
> Ot::Ot(string s){
> combo.open( "file.txt", ios::app );
> deta_f.open( s.c_str(), ios::app );
> }
>>
> void Ot::some_method (){
> deta_f << "...";
> combo << "...";
> }
>};
>>
>class Grd {
> Ot ot;
>public:
> Grd(string s):ot(s){}
>};
>>
>class Grp {
> vector<Grdgrds;
> void group_them(){
> Grd grd("something" );
> grds.push_back( grd); //<<<<<<<<<<<<<<< <<<<<<
> }
>public:
> Grp(){}
> ~Grp(){}
>};

>
just some fixes but not compiling still
>
*************** *************** *************** *************** ****
>
#include <string>
using std::string;
#include <vector>
using std::vector;
#include <fstream>
using std::ofstream;
using std::ios;
>
class Ot {
static ofstream combo;
ofstream deta_f;
public:
Ot(string s){
combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}
>
void some_method(){
deta_f << "...";
combo << "...";
}
};
>
class Grd {
Ot ot;
public:
Grd(string s):ot(s){}
};
>
class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd);
}
public:
Grp(){}
~Grp(){}
};
*************** *************** *************** *************** ****

What is the error please?

[Victor Bazarov]

Re: code syntax

Bo Yang wrote:

Gary Wessle :

>Gary Wessle <phddas@yahoo.c omwrites:
>>

>>the code below is a close parallel to the code which is generating
>>an error I am trying to fix. the error is refereeing to the line in
>>the code marked <<<<<<<<<<<<< <.
>>can you please tell if the code is correct?
>>[...]

>************** *************** *************** *************** *****

>
What is the error please?

If the compiler tries to create a copy c-tor (and it will if you don't
provide your own), it will fail since streams don't have copy c-tors.
Pushing a valud into a vector requires copy constrution. Try:

#include <fstream>
#include <vector>
class Boo {
std::fstream f;
public:
Boo(int);
};
int main() {
std::vector<Boo foo;
foo.push_back(B oo(42));
}

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[BobR]

Re: code syntax


Gary Wessle wrote in message ...

>
>just some fixes but not compiling still

Why did you not trim(remove) the old code?!?

See what Mr. Bazarov said. See my 'workaround' below....

>
>************** *************** *************** *************** *****
>#include <string>
>using std::string;
>#include <vector>
>using std::vector;
>#include <fstream>
>using std::ofstream;
>using std::ios;
>
>class Ot {
static ofstream combo;
ofstream deta_f;

std::string ID;

>public:

// Ot(string s){
Ot( string s ) : ID( s ){

combo.open( "file.txt", ios::app );
deta_f.open( s.c_str(), ios::app );
}

Ot( Ot const &cpy ){}
~Ot(){
deta_f.close();
} // Dtor
Ot& operator=( Ot const &nm ){
if( &nm == this ){ return *this;}
ID = nm.ID;
if( not deta_f.is_open( ) ){
deta_f.clear();
deta_f.open( nm.ID.c_str(),
std::ios_base:: out|std::ios_ba se::app );
} // if(!is_open)
return *this;
} // operator=(Ot const &)
// ---------------
// mote that is a candidate for exceptions. It could still fail.
// I'll let you deal with 'combo'.

>
void some_method(){
deta_f << "...";
combo << "...";
}
>};
>
>class Grd {
Ot ot;
>public:
Grd(string s):ot(s){}
>};
>
>class Grp {
vector<Grdgrds;
void group_them(){
Grd grd("something" );
grds.push_back( grd);
}
>public:
Grp(){}
~Grp(){}
>};
*************** *************** ************

In my tests, the copy constructor gets called with an empty argument, then
the assignment operator= is invoked with valid data argument.
[ adding to a 'map<string, OtMyMap; MyMap["aName"] = Ot("aName");'
approx..]


Try the changes I showed. If you have trouble, post:
1- minimal full program that demonstrates the problem.
2- the *exact* errors your compiler shows.
3- what it's doing or not doing, and what you expect.

--
Bob R
POVrookie