Databases
StackOverflow2013
Postsdbo
POInternal moving std::vector elements and QVector
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POInternal moving std::vector elements and QVector
    primarykey
    data
    text
    <p>There are two vectors <code>std :: vector</code> and <code>QVector</code>. We have to check how "shift" elements when inserted. (Is constructed two vectors with the five elements and inserted zero element) I've this code:</p> <pre><code>#include &lt;QVector&gt; #include &lt;QTextStream&gt; struct MoveTest { int i; MoveTest() {} MoveTest(const MoveTest&amp; other) {QTextStream(stdout) &lt;&lt; "constr copy" &lt;&lt; endl;} MoveTest(MoveTest &amp;&amp;other) {QTextStream(stdout) &lt;&lt; "constr move" &lt;&lt; endl;} ~MoveTest() {} inline MoveTest&amp; operator= (const MoveTest&amp; other) {QTextStream(stdout) &lt;&lt; "copy" &lt;&lt; endl;} inline MoveTest&amp; operator= (MoveTest &amp;&amp;other) {QTextStream(stdout) &lt;&lt; "move" &lt;&lt; endl;} }; int main(int argc, char *argv[]) { QTextStream(stdout) &lt;&lt; "std::move:" &lt;&lt; endl; MoveTest t1; MoveTest t2(std::move(t1)); t1 = std::move(t2); QTextStream(stdout) &lt;&lt; "QVector:" &lt;&lt; endl; QVector&lt;MoveTest&gt; qmTest(5); qmTest.insert(qmTest.begin(), MoveTest()); QTextStream(stdout) &lt;&lt; "std::vector:" &lt;&lt; endl; std::vector&lt;MoveTest&gt; mTest(5); mTest.insert(mTest.begin(), MoveTest()); return 0; } </code></pre> <p>My output with gcc 4.7.2, QMAKE_CXXFLAGS += -std=c++0x:</p> <pre><code>std::move: constr move move QVector: constr copy constr copy constr copy constr copy constr copy constr copy copy copy copy copy copy copy std::vector: constr move constr copy constr copy constr copy constr copy constr copy </code></pre> <p>How to insert elements with an internal shift without copying? What GCC flags are needed?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USInder Kumar Rathore
    1. USuser1931823
    plurals
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POInternal moving std::vector elements and QVector
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POInternal moving std::vector elements and QVector
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POInternal moving std::vector elements and QVector
      1. This table or related slice is empty.
      1. VTUpMod
    1. COa gift for you http://thbecker.net/articles/rvalue_references/section_01.html ( yeah I'm getting emotional these days ... )
      singulars
      1. POInternal moving std::vector elements and QVector
      1. USuser1824407
    2. COpossible duplicate of [How to enforce move semantics when a vector grows?](http://stackoverflow.com/questions/8001823/how-to-enforce-move-semantics-when-a-vector-grows)
      singulars
      1. POInternal moving std::vector elements and QVector
      1. USDavid Schwartz
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload