instance

I followed a number of posts on SO, and finally I can draw a conclusion that when we have something like : Person name; name is an object of class person . It becomes instance when instantiate it : name=new Person(); I am a beginner in C++, and so far I have seen we can access the functions and variables like: Person name; name.getValue; name.callFunction(); We need not to use new operator for this. So can we say the differentiating factor between an object and instance can be ignored in C++? In C++ "object" and "instance" are used nearly interchangably. There is a general programming design

I need to find a right way to prevent two running instances of my (Python) program. I am currently using the following method. On Windows, os.popen('wmic process get caption,processid | findstr `programname.exe`') On Linux, os.popen('ps x | grep `programname`') It seems to work fine for now. Is this method correct? Can someone suggest to me a better way? edit: Thanks for the reply guys, Is anything wrong with the above methods? I tried the pid file way for linux. What if the pid file gets deleted somehow? There are numerous ways: have an "instance file" in /var/run or similar (cross-platform)

I have the following class: class PluginManager { public: Handle<Value> Register(const Arguments& args); Handle<ObjectTemplate> GetObjectTemplate(); }; I want the Register method to be accessible from JavaScript. I add it to the global object like this: PluginManager pluginManagerInstance; global->Set(String::New("register"), FunctionTemplate::New(pluginManagerInstance.Register)); It throws the following error: 'PluginManager::Register': function call missing argument list; use '&PluginManager::Register' to create a pointer to member I tried to do that, but it doesn't work either. And it's not

In Python, I would like to construct an instance of the Child's class directly from an instance of the Parent class. For example: A = Parent(x, y, z) B = Child(A) This is a hack that I thought might work: class Parent(object): def __init__(self, x, y, z): print "INITILIZING PARENT" self.x = x self.y = y self.z = z class Child(Parent): def __new__(cls, *args, **kwds): print "NEW'ING CHILD" if len(args) == 1 and str(type(args[0])) == "<class '__main__.Parent'>": new_args = [] new_args.extend([args[0].x, args[0].y, args[0].z]) print "HIJACKING" return Child(*new_args) print "RETURNING FROM NEW IN

I'm trying to get my application to save some data when the orientation of the screen is changed using the onSaveInstanceState to save a boolean value mCheated . I've set numerous break points and am getting an error for the mCheated boolean value in the variables view mCheated= No such instance field: 'mCheated' I have no idea why as I declare it with a value false when the activity is started and change it to true if a button is pressed. Can anyone help me out? package com.bignerdranch.android.geoquiz; import android.app.Activity; import android.content.Intent; import android.os.Bundle;

I was under the impression that there was an instance for Either a somewhere, but I can't seem to find it. I have tried importing Control.Monad, Control.Monad.Instances and Data.Either as shown module Main where import Control.Monad import Data.Either import Control.Monad.Instances test :: [Either a b] -> Either a [b] test = sequence main = return () but ghc tells me that it could not deduce (Monad (Either a)). Adding instance Monad (Either a) where return = Right Right b >>= f = f b Left a >>= _ = Left a makes the code compile, but this instance declaration seems so general that it doesn't

I'm using Python. I've read a bit about this and can't seem to wrap my mind around it. What I want to do is have a class called Potions with various potion objects in it. For now there's one potion, a simple HealthPotion. I want potions to be stackable in inventories and shop stocks. So I need an instance of the potion amount for an inventory and an instance for each shop stock that carries potions. The potion amount would be dynamic, for buying/selling and looting of potions. If someone could provide a basic explanation or examples that would be great. Here's a snippet of what I have: class