Its value changed during the last &#39;step&#39;. Don&#39;t worry, there is nothing wrong.

&lt;!-- language-all: lang-none --&gt;

I just rebooted my computer without changing anything. Suddenly I can&#39;t open Eclipse.  Instead, I get this error message:

    ┌──────────────────────────────────────────────────────────────────────┐
    │ Eclipse                                                              │
    ├──────────────────────────────────────────────────────────────────────┤
    │                                                                      │
    │   A Java Runtime Environment (JRE) or Java Development Kit (JDK)     │
    │   must be available in order to run Eclipse. No Java virtual machine │
    │   was found after searching the following locations:                 │
    │   C:\Users\emiri\Downloads\eclipse\jre\bin\javaw.exe                 │
    │   javaw.exe in your current PATH                                     │
    │                                                                      │
    │                                                      ┌────────────┐  │
    │                                                      │     OK     │  │
    │                                                      └────────────┘  │
    └──────────────────────────────────────────────────────────────────────┘

And I see all my environment variables have been erased. `java`, `javac`, `mvn`, etc. don&#39;t work. What do I do now, and how do I fix this?


Eclipse will not open due to environment variables

I have a WinForms application with `DataGridView` control. My control has five
columns (say &quot;Name&quot;, &quot;Address&quot;, &quot;Phone&quot; etc)

I am not happy with default column width. I want to have more control over column appearance. What I want
is to be able to do one of the following:

 - Set width of each column in percent
 - Set width of each column in pixels
 - Use some other best-practive method (make width to fit text etc)

Please suggest - which property to use and how.



DataGridView - how to set column width?

what does it mean when a variable appears red in the visual studio C++ debugger? I assume not good.

Thanks. 

What does it mean when a variable appears red in the visual studio C++ debugger?

<p>what does it mean when a variable appears red in the visual studio C++ debugger? I assume not good.</p>
<p>Thanks.</p>


I have a small piece of code that depends on many static libraries (a_1-a_n). I&#39;d like to package up that code in a static library and make it available to other people. 

My static library, lets call it X, compiles fine.

I&#39;ve created a simple sample program that uses a function from X, but when I try to link it to  X, I get many errors about missing symbols from libraries a_1 - a_n.

Is there a way that I can create a new static library, Y that contains X and all the functionality needed by X (selected bits from a_1 - a_n), so that I can distribute just Y for people to link their programs to?


----------
UPDATE:

I&#39;ve looked at just dumping everything with **ar** and making one mega-lib, however, that ends up including a lot of symbols that are not needed (all the .o files are about 700 MB, however, a statically linked executable is 7 MB). Is there a nice way to include only what is actually needed?

-----------
This looks closely related to [How to combine several C/C++ libraries into one?](https://stackoverflow.com/questions/13128/how-to-combine-several-c-c-libraries-into-one &quot;Stack Overflow Question 13128&quot;).


Linking static libraries to other static libraries

I know that I can do:

    class Foo;

but can I forward declare a class as inheriting from another, like:

    class Bar {};

    class Foo: public Bar;

---

An example use case would be co-variant reference return types.

    // somewhere.h
    class RA {}
    class RB : public RA {}

... and then in another header that doesn&#39;t include somewhere.h

    // other.h
    class RA;

    class A {
     public:
      virtual RA* Foo();  // this only needs the forward deceleration
    }

    class RB : public RA; // invalid but...

    class B {
     public:
      virtual RB* Foo();  // 
    }

The only information the compiler *should* need to process the declaration of `RB* B:Foo()` is that `RB` has `RA` as a public base class. Now clearly you would need somewhere.h if you intend to do any sort of dereferencing of the return values from `Foo`. However, if some clients never calls `Foo`, then there is no reason for them to include somewhere.h which might significantly speed compilation.

In C++, is it possible to forward declare a class as inheriting from another class?

Having spent quite some time developping in C#, I noticed that if you declare an abstract class for the purpose of using it as an interface you cannot instantiate a vector of this abstract class to store instances of the children classes.

    #pragma once
    #include &lt;iostream&gt;
    #include &lt;vector&gt;
    
    using namespace std;
    
    class IFunnyInterface
    {
    public:
        virtual void IamFunny()  = 0;
    };
    
    class FunnyImpl: IFunnyInterface
    {
    public:
        virtual void IamFunny()
        {
            cout &lt;&lt; &quot;&lt;INSERT JOKE HERE&gt;&quot;;
        }
    };
    
    class FunnyContainer
    {
    private:
        std::vector &lt;IFunnyInterface&gt; funnyItems;
    };

The line declaring the vector of abstract class causes this error in MS VS2005:

    error C2259: &#39;IFunnyInterface&#39; : cannot instantiate abstract class

I see an obvious workaround, which is to replace IFunnyInterface with the following:

    class IFunnyInterface
    {
    public:
        virtual void IamFunny()
        {
            throw new std::exception(&quot;not implemented&quot;);
        }
    };

Is this an acceptable workaround C++ wise ?
If not, is there any third party library like boost which could help me to get around this ?

Thank you for reading this !

Anthony


Why can&#39;t we declare a std::vector&lt;AbstractClass&gt;?

Is there a Linux equivalent of `__declspec(dllexport)` notation for explicitly exporting a function from a shared library? For some reason with the toolchain I&#39;m using, functions that aren&#39;t class members don&#39;t appear in the resulting shared library file.

Explicitly exporting shared library functions in Linux

What is the best way to convert a std::string to bool?  I am calling a function that returns either &quot;0&quot; or &quot;1&quot;, and I need a clean solution for turning this into a boolean value.

Converting from a std::string to bool

I installed [ReSharper][1], and it works in Visual Studio, but how can I disable it?

Whenever I search in the ReSharper menu, I can&#39;t find a disable option.

  [1]: http://en.wikipedia.org/wiki/ReSharper


How can I disable ReSharper in Visual Studio and enable it again?

Is there a Page.Refresh type of command to refresh a page?

I don&#39;t want to redirect to the page or refresh in JavaScript.


Refresh Page C# ASP.NET

Let&#39;s say I wanted to create a static text file which ships with each release. I want the file to be updated with the version number of the release (as specified in `AssemblyInfo.cs`), but I don&#39;t want to have to do this manually.

I was hoping I could use a post-build event and feed the version number to a batch file like this:

    call foo.bat $(AssemblyVersion)

However I can&#39;t find any suitable variable or macro to use. 

Is there a way to achieve this that I&#39;ve missed?


Determine assembly version during a post-build event

In Visual Studio 2008, what determines the order in which projects appear within a solution folder? It&#39;s not alphabetical order, nor is it build order.

I cannot find any way of altering the order in which projects are being listed. I&#39;ve tried removing my *.suo* file, as well as moving things about in the *.sln* file. Neither had any effect.

**How can I change the order in which my projects are being displayed?**

Project Order in Visual Studio Solution

Can it be done? We&#39;re using VS2005 and VS2008 and VS2010.

I don&#39;t mean regular expressions - which have their place - but plain old text find &amp; replace. I know we can do it (at a pinch) with regular expressions using the \n tag but prefer not to get tangled up in regex escape characters, plus there&#39;s a readability issue.

If it can&#39;t be done what plain and simple (free) alternative are people using? That doesn&#39;t involve knocking up our own macro.

Multiline Find &amp; Replace in Visual Studio

I come from a Python background, where at any point in my code I can add

    import pdb; pdb.set_trace()

and at runtime I&#39;ll be dropped into an interactive interpreter at that spot. Is there an equivalent for scala, or is this not possible at runtime?

Drop into interpreter during arbitrary scala code location

I have a program that `Process.Start()` another program, and it shuts it down after N seconds. 

Sometimes I choose to attach a debugger to the started program. In those cases, I don&#39;t want the process shut down after N seconds.

I&#39;d like the host program to detect if a debugger is attached or not, so it can choose to not shut it down.

**Clarification**: I&#39;m not looking to detect if a debugger is attached to _my_ process, I&#39;m looking to detect if a debugger is attached to the process I spawned.


Is there a way to detect if a debugger is attached to another process from C#?

Is there a template tag (or any other trick) I can use to display all the variables available in a page?

Django debug display all variables of a page

I am looking for an equivalent in Chrome to the &quot;break on all errors&quot; functionality of Firebug. In the Scripts tab, Chrome has a &quot;pause on all exceptions&quot;, but this is not quite the same as breaking on all errors.

For instance, when loading a page with the following code, I would like Chrome to break on the line `foo.bar = 42`. Instead, even when enabling the &quot;Pause on all exceptions&quot;, I don&#39;t get the expected result.

    &lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Strict//EN&quot;
            &quot;http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd&quot;&gt;
    &lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot; xml:lang=&quot;en&quot; lang=&quot;en&quot;&gt;
        &lt;head&gt;
            &lt;script type=&quot;text/javascript&quot;&gt;
            
                function doError() {
                    foo.bar = 42;
                }
            
                window.onload = function() {
                    try {
                        doError();
                    } catch (e) {
                        console.log(&quot;Error&quot;, e);
                    }
                }
            &lt;/script&gt;
        &lt;/head&gt;
        &lt;body&gt;
        &lt;/body&gt;
    &lt;/html&gt;

You can try the code pasted above on [this page][1] or using this [jsFiddle][2].


  [1]: http://dl.dropbox.com/u/6900/try/ee-chrome-errors.html
  [2]: http://jsfiddle.net/avernet/KvjNB/

JavaScript: Is there a way to get Chrome to break on all errors?

Which preprocessor define should be used to specify debug sections of code?

Use `#ifdef _DEBUG` or `#ifndef NDEBUG` or is there a better way to do it, e.g. `#define MY_DEBUG`?

I think `_DEBUG` is Visual Studio specific, is NDEBUG standard?

_DEBUG vs NDEBUG

Why does the following work?

    &lt;something&gt;.stop().animate(
        { &#39;top&#39; : 10 }, 10
    );

Whereas this doesn&#39;t work:

    var thetop = &#39;top&#39;;
    &lt;something&gt;.stop().animate(
        { thetop : 10 }, 10
    );

To make it even clearer: At the moment I&#39;m not able to pass a CSS property to the animate function as a variable.


How to use a variable for a key in a JavaScript object literal?

I&#39;ve been hearing these two words used in Microsoft tutorials for VB.NET. What is the difference between these two words when used in reference to variables?

What is the difference between &quot;instantiated&quot; and &quot;initialized&quot;?

I am coming from c# where this was easy, and possible.

I have this code:

    public abstract class clsAbstractTable {
    	
    	public abstract String TAG;
        public abstract void init();
    
    }

but Eclipse tells me I use illegal modifier. 

I have this class:

    public class clsContactGroups extends clsAbstractTable {
    
    	
    }

I want the variable and method defined in such way, that Eclipse to **prompt me**, I have unimplemented abstract **variables** and methods.

How do I need to define my abstract class so I should be prompted to implement the abstracts?

**EDIT 1**

I will create different classes for different db tables. Each class should have it&#39;s own TABLENAME variable, no exception. I have to make sure this variable is static each time when I create a new class that extends the abstract class.

Then in the abstract class I will have a method eg: init();

If in this init() method I call TABLENAME, it should take the value from the sub-class.

something like this should also work out

    String tablename=(clsAbstract)objItem.TABLENAME;
    // where objItem can be any class that extended clsAbstract;

**EDIT 2**

I want a constant(static) defined in each class having it&#39;s name defined in abstract. 

 - I define variable TABLENAME in abstract, but no value given.
 - I create a clsContactGroups, I should be prompted to implement TABLENAME, this is where gets some data. eg: TABLENAME=&quot;contactgroups&quot;;
 - I create a second class clsContacts, I should be prompted to implement TABLENAME, this is where gets some data. eg: TABLENAME=&quot;contacts&quot;;  
etc...

Abstract variables in Java?

In PHP, you can declare constants in two ways:

1. With `define` keyword

    ```PHP
    define(&#39;FOO&#39;, 1);
    ```

2. Using `const` keyword

    ```PHP
    const FOO = 1;
    ```

----------

- What are the main differences between those two?
- When and why should you use one and when use the other?



Content Type	Original Author	Original Content on Stackoverflow
Question	T.T.T.	View Question on Stackoverflow
Solution 1 - C++	Trent	View Answer on Stackoverflow

What does it mean when a variable appears red in the visual studio C++ debugger?

C++ Problem Overview

C++ Solutions

Solution 1 - C++

DataGridView - how to set column width?

Eclipse will not open due to environment variables

Attributions