Binary Compatibility Workarounds: Difference between revisions

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[[Category:Developing_Qt]]
[[Category:Developing_Qt::Guidelines]]


= Binary Compatibility Workarounds =
This page describes some workarounds for keeping binary compatibility in patch releases. You should read the KDE reference: [https://community.kde.org/Policies/Binary_Compatibility_Issues_With_C%2B%2B Binary Compatibility Issues with C++].


This page describes some workarounds for keeping binary compatibility in patch releases.
Specifically, the d-pointer technique is explained in much detail in [[D-Pointer|D-Pointer: What Private Implementation is and how it works]].
 
You should read the KDE reference: http://techbase.kde.org/Policies/Binary_Compatibility_Issues_With_C++


== Declaring a slot for private classes (d-pointer) ==
== Declaring a slot for private classes (d-pointer) ==
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Use a Q_PRIVATE_SLOT:
Use a Q_PRIVATE_SLOT:


<code><br /> class A: public QObject<br /> {<br /> Q_OBJECT<br /> <br /> private:<br /> Q_PRIVATE_SLOT(d_func(), void myPrivateSlot())<br /> };
<code lang="cpp">
class A: public QObject
{
Q_OBJECT
private:
Q_PRIVATE_SLOT(d_func(), void myPrivateSlot())
};
 
/* in .cpp file */
 
void APrivate::myPrivateSlot() {…}
 
#include "moc_a.cpp"
</code>
 
Pitfalls to avoid:


/* in .cpp file '''/
* ''' Don't include `a.moc`, but `moc_a.cpp` in your .cpp file
<br /> void APrivate::myPrivateSlot() {…}
* Q_PRIVATE_SLOT takes the complete signature of the private slot, not just its name
<br /> #include &quot;moc_a.cpp&amp;quot;<br /></code>
<br />Pitfalls to avoid:
<br />''' Don't include `a.moc`, but `moc_a.cpp` in your .cpp file<br />* Q_PRIVATE_SLOT takes the complete signature of the private slot, not just its name

Latest revision as of 13:43, 25 August 2017


This page describes some workarounds for keeping binary compatibility in patch releases. You should read the KDE reference: Binary Compatibility Issues with C++.

Specifically, the d-pointer technique is explained in much detail in D-Pointer: What Private Implementation is and how it works.

Declaring a slot for private classes (d-pointer)

Use a Q_PRIVATE_SLOT:

 class A: public QObject
 {
 Q_OBJECT
 
 private:
 Q_PRIVATE_SLOT(d_func(), void myPrivateSlot())
 };

/* in .cpp file */

 void APrivate::myPrivateSlot() {}

 #include "moc_a.cpp"

Pitfalls to avoid:

  • Don't include `a.moc`, but `moc_a.cpp` in your .cpp file
  • Q_PRIVATE_SLOT takes the complete signature of the private slot, not just its name