Use QString&#39;s number method (docs are [here][1]):

    double valueAsDouble = 1.2;
    QString valueAsString = QString::number(valueAsDouble);


  [1]: https://doc.qt.io/qt-5/qstring.html#number-2

Instead of `QString::number()` i would use [`QLocale::toString()`][1], so i can get locale aware group seperatores like german &quot;1.234.567,89&quot;.

  [1]: https://doc.qt.io/qt-5/qlocale.html#toString-6

Building on @Kristian&#39;s answer, I had a desire to display a fixed number of decimal places.  That can be accomplished with other arguments in the `QString::number(...)` function. For instance, I wanted 3 decimal places:

    double value = 34.0495834;
    QString strValue = QString::number(value, &#39;f&#39;, 3);
    // strValue == &quot;34.050&quot;

The `&#39;f&#39;` specifies decimal format notation (more info [here](http://doc.qt.io/qt-5/qstring.html#argument-formats), you can also specify scientific notation) and the `3` specifies the precision (number of decimal places).  Probably already linked in other answers, but more info about the `QString::number` function can be found [here in the `QString` documentation](http://doc.qt.io/qt-5/qstring.html)

You can use arg(), as follow:

    double dbl = 0.25874601;
    QString str = QString(&quot;%1&quot;).arg(dbl);

This overcomes the problem of: &quot;Fixed precision&quot; at the other functions like: setNum() and number(), which will generate random numbers to complete the defined precision

Check out the [documentation][1]

Quote:

&gt; QString provides many functions for
&gt; converting numbers into strings and
&gt; strings into numbers. See the [arg()][2]
&gt; functions, the [setNum()][3] functions, the
&gt; [number()][4] static functions, and the
&gt; [toInt()][5], [toDouble()][6], and similar
&gt; functions.


  [1]: http://doc.qt.io/qt-4.8/qstring.html
  [2]: http://doc.qt.io/qt-4.8/qstring.html#arg
  [3]: http://doc.qt.io/qt-4.8/qstring.html#setNum
  [4]: http://doc.qt.io/qt-4.8/qstring.html#number
  [5]: http://doc.qt.io/qt-4.8/qstring.html#toInt
  [6]: http://doc.qt.io/qt-4.8/qstring.html#toDouble

My question is somewhat similar to this
[&quot;How to stop debugging (or detach process) without stopping the process?&quot;][1]

but i want to detach from one process.

for instance, I have a windows form app which i also attach to a windows service. I want to detach from only service (detach all will remove debugging from all executions and hence i won&#39;t be able to debug other application).

P.S: If possible please mention for visual studio 2008 and 2010.

  [1]: https://stackoverflow.com/questions/2671503/how-to-stop-debugging-or-detach-process-without-stopping-the-process

detach one process from visual studio debugger

I&#39;m using Git 1.7.4.1 on Mac 10.6.6.  From the command line, how do I commit changes in only a single directory?  I added the directory by doing:

    git add my-dir

but doing

    git commit -a

brings up a list of all changes in my repo, and I only want to commit and push changes from `my-dir`.

Commit changes only in one directory in Git

I am writing a program in QT. I want to convert a `double` into a `Qstring` in C++.

Convert a double to a QString

<p>I am writing a program in QT. I want to convert a <code>double</code> into a <code>Qstring</code> in C++.</p>


Can someone please tell me how to create a static library from a .cpp and a .hpp file? Do I need to create the .o and the .a? I would also like to know how can I compile a static library in and use it in other .cpp code. I have `header.cpp`, `header.hpp .` I would like to create `header.a`. Test the header.a in `test.cpp`. I am using g++ for compiling.

How to create a static library with g++?

I&#39;m writing a little piece of code where I&#39;ll have to insert values into a C++ STL vector at a certain place depending on values in the vector elements. I&#39;m using the `insert()` function to accomplish this. I realize that when I want to add a new element to the end of the vector, I could simply use `push_back()`. But to keep my code looking nice, I&#39;d like to exclusively use `insert()`, which takes as input the iterator pointing to the element after the desired insertion point and the value to be inserted. If the value of the iterator passed in as an argument is `v.end()`, where `v` is my vector, will this work the same as `push_back()`? 

Thanks a lot!

Using C++ vector::insert() to add to end of vector

I&#39;ve been working on some C++ code that a friend has written and I get the following error that I have never seen before when compiling with gcc4.6:

    error: use of deleted function

    ‘GameFSM_&lt;std::array&lt;C, 2ul&gt; &gt;::hdealt::hdealt()’ is implicitly deleted because the default definition would be ill-formed:
    uninitialized non-static const member ‘const h_t FlopPokerGameFSM_&lt;std::array&lt;C, 2ul&gt; &gt;::hdealt::h’


Edit: This comes from a part of the code using boost MSM: [Boost Webpage][1]

Edit2: There is no `= delete()` used anywhere in the sourcecode.

Generally speaking, what does this error mean? What should I be looking for when this type of error occurs?


  [1]: http://www.boost.org/doc/libs/1_46_1/libs/msm/doc/HTML/index.html

error: use of deleted function

Why should i do something like this:

    inline double square (double x) { return x*x;}

instead of 

    double square (double x) { return x*x;}

Is there a difference?

c++ inline function?

    #include &lt;iostream&gt;
    #include &lt;set&gt;

    using namespace std;

    class StudentT {

    public:
        int id;
        string name;
    public:
        StudentT(int _id, string _name) : id(_id), name(_name) {
        }
        int getId() {
            return id;
        }
        string getName() {
            return name;
        }
    };

    inline bool operator&lt; (StudentT s1, StudentT s2) {
        return  s1.getId() &lt; s2.getId();
    }

    int main() {

        set&lt;StudentT&gt; st;
        StudentT s1(0, &quot;Tom&quot;);
        StudentT s2(1, &quot;Tim&quot;);
        st.insert(s1);
        st.insert(s2);
        set&lt;StudentT&gt; :: iterator itr;
        for (itr = st.begin(); itr != st.end(); itr++) {
            cout &lt;&lt; itr-&gt;getId() &lt;&lt; &quot; &quot; &lt;&lt; itr-&gt;getName() &lt;&lt; endl;
        }
        return 0;
    }

In line:

    cout &lt;&lt; itr-&gt;getId() &lt;&lt; &quot; &quot; &lt;&lt; itr-&gt;getName() &lt;&lt; endl;

It give an error that:

&gt;../main.cpp:35: error: passing &#39;const StudentT&#39; as &#39;this&#39; argument of &#39;int StudentT::getId()&#39; discards qualifiers
&gt;
&gt;../main.cpp:35: error: passing &#39;const StudentT&#39; as &#39;this&#39; argument of &#39;std::string StudentT::getName()&#39; discards qualifiers

What&#39;s wrong with this code? Thank you!

error: passing xxx as &#39;this&#39; argument of xxx discards qualifiers

Does C++ have any equivalent to python&#39;s function `os.path.join`? Basically, I&#39;m looking for something that combines two (or more) parts of a file path so that you don&#39;t have to worry about making sure the two parts fit together perfectly. If it&#39;s in Qt, that would be cool too.

Basically I spent an hour debugging some code and at least part of it was because `root + filename` had to be `root/ + filename`, and I&#39;m looking to avoid that in the future.

How to build a full path string (safely) from separate strings?

I have a list of integers that I need to iterate over but an array is inadequate.
What are the differences between `vectors` and `lists` and is there anything I need to know before I pick a type?

Just to be clear, I&#39;ve read the QT docs but this is the extent of what I know:

&gt;  `QList&lt;T&gt;`, `QLinkedList&lt;T&gt;`, and `QVector&lt;T&gt;` provide similar functionality. Here&#39;s an overview:
&gt;
 - For most purposes, `QList` is the right class to use. Its index-based API is more convenient than `QLinkedList&#39;s` iterator-based API, and it is usually faster than `QVector` because of the way it stores its items in memory. It also expands to less code in your executable.
 - If you need a real linked list, with guarantees of constant time insertions in the middle of the list and iterators to items rather than indexes, use `QLinkedList`.
 - If you want the items to occupy adjacent memory positions, use `QVector`.


QVector vs QList

I would like to locate the folder where Qt Creator saves all its settings (text editor preferences, syntax highlighting, etc.) so that I can back them up. Does anybody know where they are?

Where does Qt Creator save its settings?

I am exploring Qt source code and came across this `Q_D` macro. Could some one please explain what it does? 

Almost all the time it should return a widget of the type given as a parameter which is the `d` variable. Need more clarification on this.


What does Q_D macro do in Qt

Is there a way to change a .pro , .ui and .h names if the project is done? How to do it?

Content Type	Original Author	Original Content on Stackoverflow
Question	Nagaraju	View Question on Stackoverflow
Solution 1 - C++	Kristian	View Answer on Stackoverflow
Solution 2 - C++	Lars	View Answer on Stackoverflow
Solution 3 - C++	yano	View Answer on Stackoverflow
Solution 4 - C++	Tarek.Mh	View Answer on Stackoverflow
Solution 5 - C++	jwd	View Answer on Stackoverflow

Convert a double to a QString

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Solution 3 - C++

Solution 4 - C++

Solution 5 - C++

Commit changes only in one directory in Git

detach one process from visual studio debugger

Attributions