blocks|key|654911|text|要使用不绑定到类实例的成员函数，必须声明方法static|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|654912|static+void+deleter(int*+value)+{
++++delete+value;
}|code-block|syntax|javascript|654913|entityMap^0|M|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

To use a member function that isn't bound to an instance of your class you'd have to declare the method <code>static</code>

<pre><code>static void deleter(int* value) {
 delete value;
}
</code></pre>

blocks|key|2682208|text|如果要使用非静态成员函数作为删除器，则必须将其绑定到实例--但请注意，当调用删除器时，实例仍需处于活动状态。例如,|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2682209|class+ShorterName+{
public:
++++ShorterName(void)+{
++++++++using+namespace+std::placeholders;
++++++++auto+a+=+std::shared_ptr<int>(new+int(1),
+++++++++++++++++++std::bind(&A::deleter,+this,+_1));
++++}

++++void+deleter(int*+value)+{
++++++++delete+value;
++++}
};|code-block|syntax|javascript|2682210|如果不需要特定实例，则可以使函数保持静态，因此它不需要实例。|2682211|class+ShorterName+{
public:
++++ShorterName(void)+{
++++++++auto+a+=+std::shared_ptr<int>(new+int(1),+deleter);
++++}

++++static+void+deleter(int*+value)+{
++++++++delete+value;
++++}
};|2682212|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you want to use a non-static member function as a deleter, you have to bind it to an instance&mdash;but note that the instance would need to still be alive when the deleter is invoked. For example,

<pre><code>class ShorterName {
public:
 ShorterName(void) {
 using namespace std::placeholders;
 auto a = std::shared_ptr&lt;int&gt;(new int(1),
 std::bind(&amp;A::deleter, this, _1));
 }

 void deleter(int* value) {
 delete value;
 }
};
</code></pre>

If you don't need a particular instance, you can make the function static, so it doesn't require an instance.

<pre><code>class ShorterName {
public:
 ShorterName(void) {
 auto a = std::shared_ptr&lt;int&gt;(new int(1), deleter);
 }

 static void deleter(int* value) {
 delete value;
 }
};
</code></pre>

blocks|key|654988|text|有几种方法可以解决这个问题。如果您实际上是指一个非静态成员函数，那么其中一种方法(并不是唯一的方法)是通过lambda函数实现的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|654989|class+MemberFunctionPointerInConstructor+{
public:
++++MemberFunctionPointerInConstructor()+{
++++++++std::shared_ptr<int>+a+=+std::shared_ptr<int>(
++++++++++++new+int(1),+
++++++++++++[this](int+*p){this->deleter(p);});++
++++}+++

++++void+deleter(int*+value)+{
++++++++delete+value;
++++}+++
};++|code-block|syntax|javascript|654990|entityMap|0|LINK|mutability|MUTABLE|url|http://en.cppreference.com/w/cpp/language/lambda^0|1H|8|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

There are several ways to solve this. If you actually mean a non-static member function, one way of doing so (not the only one) would be through a <a href="http://en.cppreference.com/w/cpp/language/lambda" rel="nofollow">lambda function</a>:

<pre><code>class MemberFunctionPointerInConstructor {
public:
 MemberFunctionPointerInConstructor() {
 std::shared_ptr&lt;int&gt; a = std::shared_ptr&lt;int&gt;(
 new int(1), 
 [this](int *p){this-&gt;deleter(p);}); 
 } 

 void deleter(int* value) {
 delete value;
 } 
}; 
</code></pre>

blocks|key|353003|text|答案很简单。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|353004|static+void+deleter(int*+value)+{
++++delete+value;
}|code-block|syntax|javascript|353005|您必须使函数是静态的，因为否则它可能会使用该类的成员变量，只有在有一个实例可以执行时才能这样做，而这里不是这样的。|353006|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

The answer is very simple.

<pre><code>static void deleter(int* value) {
 delete value;
}
</code></pre>

You must make the function static, because otherwise it might use member variables of that class, which can be only done if there is an instance for it to be done with, and here that is not the case.

I tried to use std::shared_pointer with deleter. I tried to use a member function as the deleter. However it could not compiled. Compiler gave me a error message but I could not understand why it did not work. Does someone knows why it did not work? Thank you very much.

Simplified code is following,

<pre><code>#include &lt;memory&gt;

class MemberFunctionPointerInConstructor {
public:
 MemberFunctionPointerInConstructor(void) {
 std::shared_ptr&lt;int&gt; a = std::shared_ptr&lt;int&gt;(new int(1), deleter); // this line makes a compiler error message
 }

 void deleter(int* value) {
 delete value;
 }
};
</code></pre>

The error message from compiler is following,

<pre><code>error: invalid use of non-static member function
std::shared_ptr&lt;int&gt; a = std::shared_ptr&lt;int&gt;(new int(1), deleter);
 ^
</code></pre>

Thank you very much.

member function pointer in constructor

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我尝试在删除器中使用std::shared_pointer。我尝试使用一个成员函数作为删除器。然而，它无法编译。编译器给了我一条错误消息，但我不明白为什么它不能工作。有人知道它为什么不起作用吗？非常感谢。简化代码如下，#include <memory>class MemberFunctionPointerInConst...

问构造函数中的成员函数指针
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