If you want to append *copies of items* in B, you can do:
 
    a.insert(a.end(), b.begin(), b.end());

If you want to *move items* of B to the end of A (emptying B at the same time), you can do:

    a.splice(a.end(), b);

In your situation splicing would be better, since it just involves adjusting a couple of pointers in the linked lists.

one example using boost

    std::list&lt;T&gt; A; // object A is a list containing T structure
    std::list&lt;T&gt; B; // object B is a list containing T structure
    
    // append list B to list A
    BOOST_FOREACH(auto &amp;listElement, B) { A.push_back( listElement ); }

I have a .Net Windows service. I want to create an installer to install that windows service.

Basically, it has to do the following:

 1. Pack `installutil.exe` (Is it required?) 
 2. Run `installutil.exe` MyService.exe 
 3. Start MyService

Also, I want to provide an uninstaller which runs the following command:

    installutil.exe /u MyService.exe

How to do these using Inno Setup?

Inno Setup for Windows service?

I have a `vector&lt;int&gt;` container that has integers (e.g. {1,2,3,4}) and I would like to convert to a string of the form 

    &quot;1,2,3,4&quot;

What is the cleanest way to do that in C++?
In Python this is how I would do it:

    &gt;&gt;&gt; array = [1,2,3,4]
    &gt;&gt;&gt; &quot;,&quot;.join(map(str,array))
    &#39;1,2,3,4&#39;





Convert a vector&lt;int&gt; to a string

in C++, I have two `list&lt;T&gt;` objects `A` and `B` and I want to add all the members of `B` to the end of `A`. I&#39;ve searched a few different sources and haven&#39;t found a simple solution (e.i. `A.append(B);`) and this surprises me a bit.

*What is the best way to do this?*

As it happens, I don&#39;t care about B after this (it gets deleted in the very next line) so if there is a way to leverage that for better perf I&#39;m also interested in that.

how to append a list&lt;T&gt; object to another

in C++, I have two <code>list&#x3C;T></code> objects <code>A</code> and <code>B</code> and I want to add all the members of <code>B</code> to the end of <code>A</code>. I've searched a few different sources and haven't found a simple solution (e.i. <code>A.append(B);</code>) and this surprises me a bit.
What is the best way to do this?
As it happens, I don't care about B after this (it gets deleted in the very next line) so if there is a way to leverage that for better perf I'm also interested in that.

I&#39;ve been told by others that writing `using namespace std;` in code is wrong, and that I should use `std::cout` and `std::cin` directly instead.

Why is `using namespace std;` considered a bad practice? Is it inefficient or does it risk declaring ambiguous variables (variables that share the same name as a function in `std` namespace)? Does it impact performance?

Why is &quot;using namespace std;&quot; considered bad practice?

I am trying this code on GNU&#39;s C++ compiler and am unable to understand its behaviour:

    #include &lt;stdio.h&gt;;

    int main()
    {
        int  num1 = 1000000000;
        long num2 = 1000000000;
        long long num3;
        //num3 = 100000000000;
        long long num4 = ~0;

        printf(&quot;%u %u %u&quot;, sizeof(num1), sizeof(num2), sizeof(num3));
        printf(&quot;%d %ld %lld %llu&quot;, num1, num2, num3, num4);
        return 0;
    }

When I uncomment the commented line, the code doesn&#39;t compile and is giving an error:

&gt; error: integer constant is too large for long type

But, if the code is compiled as it is and is executed, it produces values much larger than 10000000000.

Why?


long long in C/C++

How do you set application icon for application made using Qt? Is there some easy way? It&#39;s a qmake-based project.

How to set application icon in a Qt-based project?

I am looking to compare two arrays in google test. In UnitTest++ this is done through CHECK_ARRAY_EQUAL. How do you do it in google test?

Comparison of arrays in google test?

What is array to pointer decay? Is there any relation to array pointers?


What is array to pointer decay?

Say I have:

    IList&lt;Person&gt; people = new List&lt;Person&gt;();

And the person object has properties like FirstName, LastName, and Gender.

How can I convert this to a list of properties of the Person object.  For example, to a list of first names.

    IList&lt;string&gt; firstNames = ???

C#: How to convert a list of objects to a list of a single property of that object?

I have a float[] and i would like to get a list with the same elements. I could do the ugly thing of adding them one by one but i wanted to use the Arrays.asList method. There is a problem though. This works:

    List&lt;Integer&gt; list = Arrays.asList(1,2,3,4,5);

But this does not.

    int[] ints = new int[] {1,2,3,4,5};
    List&lt;Integer&gt; list = Arrays.asList(ints);

The asList method accepts a varargs parameter which to the extends of my knowledge is a &quot;shorthand&quot; for an array. 

Questions:  

  - Why does the second piece of code returns a `List&lt;int[]&gt;` but not `List&lt;int&gt;`.

  - Is there a way to correct it?

  - Why doesn&#39;t autoboxing work here; i.e. `int[]` to `Integer[]`?

Arrays.asList() not working as it should?

I&#39;m trying to read a CSV file into a list of lists (of strings), pass it around for getting some data from a database, build a new list of lists of new data, then pass that list of lists so it can be written to a new CSV file. _I&#39;ve looked all over, and I can&#39;t seem to find an example on how to do it_. 

I&#39;d rather not use simple arrays since the files will vary in size and I won&#39;t know what to use for the dimensions of the arrays. I have no issues dealing with the files. I&#39;m just not sure how to deal with the list of lists.

Most of the examples I&#39;ve found will create multi-dimensional arrays or perform actions inside the loop that&#39;s reading the data from the file. I know I can do that, but I want to write object-oriented code. If you could provide some example code or point me to a reference, that would be great.

Working with a List of Lists in Java

Why is `list.size()&gt;0` slower than `list.isEmpty()` in Java? On other words why `isEmpty()` is preferable over `size()&gt;0`?


When I look at the implementation in `ArrayList`, then it looks like the speed should be the same:

**ArrayList.size()**

        /**
         * Returns the number of elements in this list.
         *
         * @return the number of elements in this list
         */
        public int size() {
    	  return size;
        }

**ArrayList.isEmpty()**
   

        /**
         * Returns &lt;tt&gt;true&lt;/tt&gt; if this list contains no elements.
         *
         * @return &lt;tt&gt;true&lt;/tt&gt; if this list contains no elements
         */
        public boolean isEmpty() {
            return size == 0;
         }
     
If we just write a simple program to get the time take by both the methods, that case `size()` will take more `isEmpty()` in all cases, why this so?

Here is my TestCode;

    import java.util.List;
    import java.util.Vector;
    
    public class Main {
        public static void main(String[] args) {
            List l=new Vector();
            int i=0;
            for(i=0;i&lt;10000;i++){
                l.add(new Integer(i).toString());
            }
            System.out.println(i);
            Long sTime=System.nanoTime();
            l.size();
            Long eTime=System.nanoTime();
            l.isEmpty();
            Long eeTime=System.nanoTime();
            System.out.println(eTime-sTime);
            System.out.println(eeTime-eTime);
        }
    }


Here `eTime-sTime&gt;eeTime-eTime` in all cases. Why?

Why is list.size()&gt;0 slower than list.isEmpty() in Java?

What is an efficient way to find the most common element in a Python list?

My list items may not be hashable so can&#39;t use a dictionary.
Also in case of draws the item with the lowest index should be returned. Example:

    &gt;&gt;&gt; most_common([&#39;duck&#39;, &#39;duck&#39;, &#39;goose&#39;])
    &#39;duck&#39;
    &gt;&gt;&gt; most_common([&#39;goose&#39;, &#39;duck&#39;, &#39;duck&#39;, &#39;goose&#39;])
    &#39;goose&#39;

Find the most common element in a list

I&#39;m trying to delete everything from a `std::vector` by using the following code

    vector.erase( vector.begin(), vector.end() );

but it doesn&#39;t work.

----

Update: Doesn&#39;t clear destruct the elements held by the vector? I don&#39;t want that, as I&#39;m still using the objects, I just want to empty the container

Delete all items from a c++ std::vector

Using C++, and hopefully the standard library, I want to sort a sequence of samples in ascending order, but I also want to remember the original indexes of the new samples.

For example, I have a set, or vector, or matrix of samples `A : [5, 2, 1, 4, 3]`. I want to sort these to be  `B : [1,2,3,4,5]`, but I also want to remember the original indexes of the values, so I can get another set which would be:
 `C : [2, 1, 4, 3, 0 ]` - which corresponds to the index of each element in &#39;B&#39;, in the original &#39;A&#39;.

For example, in Matlab you can do:

     [a,b]=sort([5, 8, 7])
     a = 5 7 8
     b = 1 3 2

Can anyone see a good way to do this?

C++ sorting and keeping track of indexes

I like vectors a lot. They&#39;re nifty and fast. But I know this thing called a valarray exists. Why would I use a valarray instead of a vector? I know valarrays have some syntactic sugar, but other than that, when are they useful?

C++ valarray vs. vector

At the moment my solution is to iterate through the map to solve this.

I see there is a `upper_bound` method which can make this loop faster, but is there a quicker or more succinct way?

C++ How to find the biggest key in a std::map?

What&#39;s the difference between `std::string` and `std::basic_string`? And why are both needed?

Content Type	Original Author	Original Content on Stackoverflow
Question	BCS	View Question on Stackoverflow
Solution 1 - C++	UncleBens	View Answer on Stackoverflow
Solution 2 - C++	serup	View Answer on Stackoverflow

how to append a list<T> object to another

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Convert a vector<int> to a string

Inno Setup for Windows service?

Attributions