Hi,
I have a base class and derived a class from the base class, i want to print & read the data for the object created for the derived class,so i have overloaded both the << and >> operators and also have done the foward declaration.
Below is the code snippet,
#include <iostream>
class... (3 Replies)
im just trying to have some fun and kill some time writing a c++ program that has a person type in a car make and model then gives them a year and a price. or something like that. i always have problems getting it goin but once the ball is rolling im usually pretty good. anyone wanna help me out? ... (1 Reply)
Hi, i have a question about C++. Is it possible to declare a class with a member ot the same class? For example, a linked list or i want to convert this C code to C++ class (Elemento)
typedef struct elemento
{
char name;
char value;
List<struct elemento> ltElementos;
... (7 Replies)
Hi friends,
The derived class cannot access the base class's variables in my program. You can have a look at my code, I am actually using class templates.
#include <iostream>
using namespace std;
template <class T>
class Sum
{
friend void Check(Sum &s, T a, T b)
{
T x,... (2 Replies)
Hi,
I believe the next code is wrong:
class Egg {
Egg e;
int i;
Egg(int ii=0) : i(ii) {}
};
because you would end up with an endless definition (memory allocation) of Egg objects, thus int i.
Ok, so God Eckel proposes for a singleton:
class Egg {
static Egg e;
int... (5 Replies)
Hi all!
I am trying to register a device in an existing device class, but I am
having trouble getting the pointer to an existing class.
I can create a class in a module, get the pointer to it and then use
it to register the device with:
*cl = class_create(THIS_MODULE, className);... (0 Replies)
Hello All,
I am a learner in C++. I was testing my inheritance knowledge with following piece of code.
#include <iostream>
using namespace std;
class base
{
public :
void display()
{
cout << "In base display()" << endl;
}
void display(int k)
{... (2 Replies)
Dear All,
I have a requests to retrieve all lines if second line last columns meets certain criteria.
Here is the output of the result
Table: DSSBDW.DA_MASK_CLK_AR
120908 0 86 86 - 1934528 0 70 100 -*-
Table: DSSBDW.DA_MASK_CLK_IP
310657 22030 143 185 - 5281169 7 88 77 *-*
Table:... (5 Replies)
Discussion started by: ckwan123
5 Replies
LEARN ABOUT DEBIAN
tk::derived
Derived(3pm) User Contributed Perl Documentation Derived(3pm)NAME
Tk::Derived - Base class for widgets derived from others
SYNOPSIS
package Tk::MyNewWidget;
use Tk::widgets qw/ BaseWidget, list of Tk widgets /;
use base qw/ Tk::Derived Tk::BaseWidget /;
Construct Tk::Widget 'MyNewWidget';
sub ClassInit {
my( $class, $mw ) = @_;
#... e.g., class bindings here ...
$class->SUPER::ClassInit( $mw );
}
sub Populate {
my( $self, $args ) = @_;
my $flag = delete $args->{-flag};
if( defined $flag ) {
# handle -flag => xxx which can only be done at create
# time the delete above ensures that new() does not try
# and do $self->configure( -flag => xxx );
}
$self->SUPER::Populate( $args );
$self = $self->Component( ... );
$self->Delegates( ... );
$self->ConfigSpecs(
'-cursor' => [ SELF, 'cursor', 'Cursor', undef ],
'-something' => [ METHOD, dbName, dbClass, default ],
'-text' => [ $label, dbName, dbClass, default ],
'-heading' => [ {-text => $head},
heading, Heading, 'My Heading' ],
);
}
sub something {
my( $self, $value) = @_;
if ( @_ > 1 ) {
# set it
}
return # current value
}
DESCRIPTION
Tk::Derived is used with Perl's multiple inheritance to override some methods normally inherited from Tk::Widget.
Tk::Derived should precede any Tk widgets in the class's base class definition.
Tk::Derived's main purpose is to apply wrappers to "configure" and "cget" methods of widgets to allow the derived widget to add to or
modify behaviour of the configure options supported by the base widget.
The derived class should normally override the "Populate" method provided by Tk::Derived and call "ConfigSpecs" to declare configure
options.
The public methods provided by Tk::Derived are as follows:
->ConfigSpecs(-key => [kind, name, Class, default], ...)
SEE ALSO
Tk::ConfigSpecs Tk::mega Tk::composite
perl v5.14.2 2010-05-29 Derived(3pm)