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$self special variable for %extend

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git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@9530 626c5289-ae23-0410-ae9c-e8d60b6d4f22
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William S Fulton 2006-11-08 00:54:28 +00:00
commit 1a439a9e19
8 changed files with 62 additions and 30 deletions
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35
Doc/Manual/SWIGPlus.html
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@ -2734,7 +2734,7 @@ public:
%extend {
char *__str__() {
static char temp[256];
sprintf(temp,"[ %g, %g, %g ]", self->x,self->y,self->z);
sprintf(temp,"[ %g, %g, %g ]", $self->x,$self->y,$self->z);
return &temp[0];
}
}
@ -2760,10 +2760,37 @@ command.
</pre></div>
<p>
The C++ 'this' pointer is often needed to access member variables, methods etc.
The <tt>$self</tt> special variable should be used wherever you could use 'this'.
The example above demonstrates this for accessing member variables.
The implicit 'this' pointer that is present in C++ methods is not present in <tt>%extend</tt> methods.
In order to access anything in the extended class or its base class, an explicit 'this' is required.
The following example shows how one could access base class members:
</p>
<div class="code"><pre>
struct Base {
virtual void method(int v) {
...
}
int value;
};
struct Derived : Base {
};
%extend Derived {
virtual void method(int v) {
$self-&gt;Base::method(v);
$self-&gt;value = v;
...
}
}
</pre></div>
<p>
The<tt> %extend</tt> directive follows all of the same conventions
as its use with C structures. Please refer to the <a href="SWIG.html#SWIG">SWIG Basics</a>
chapter for further details.
as its use with C structures. Please refer to the <a href="SWIG.html#SWIG_adding_member_functions">Adding member functions to C structures</a>
section for further details.
</p>
<p>
@ -3446,7 +3473,7 @@ It is also possible to separate these declarations from the template class. For
}
/* Make a copy */
T *__copy__() {
return new List&lt;T&gt;(*self);
return new List&lt;T&gt;(*$self);
}
};