在单例中使用已删除的副本构造函数 [英] Use of deleted copy constructor in the singleton

问题描述

我已经实现了单例模式，例如这，这里是我的代码：

I've implemented the singleton pattern like this, there is my code:

头文件：

class Settings_manager{
public:
    static Settings_manager& get_instance();

    void operator=(Settings_manager const&) =delete;
    Settings_manager(Settings_manager const&) =delete;
...

private:
    Settings_manager();
};

实现：

Settings_manager& Settings_manager::get_instance()
{
    static Settings_manager instance;
    return instance;
}

Settings_manager::Settings_manager()
{
    read_file();
}

当我尝试使用 get_instance main 中的c>函数是这样的：

When I try use get_instance function in main like this:

Settings_manager set = Settings_manager::get_instance();

或 Settings_manager set = std :: move（Settings_manager :: get_instance（） ）;

我得到

error: use of deleted function 'Settings_manager::Settings_manager(const Settings_manager&)'
 Settings_manager set = Settings_manager::get_instance();

有人可以说出什么问题并加以解释吗？谢谢。

Can somebody tell, what's wrong and explain it? Thanks.

推荐答案

在这里考虑您要执行的操作：

Consider what you're trying to do here:

Settings_manager set = Settings_manager::get_instance();

您有自己的单身， get_instance（） ，并且您要复制它？如果您可以...创建其中两个，那将有可能破坏单例的目的？

You have your singleton, get_instance(), and you're trying to copy it? That would kind of defeat the purpose of singleton if you could just... create two of them right?

您要使用引用 ：

Settings_manager& set = Settings_manager::get_instance();

这样， set 是单例实例。不是它的副本。

This way, set is the singleton instance. Not a copy of it.

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