C++ 知道禁用 copy-ctor/assign operator 是 C++ 程序员的试金石

陈硕CSDN博客 ：知道禁用 copy-ctor/assign operator 是 C++ 程序员的试金石

vgxpm的专栏：C++之实现禁用 copy-ctor/assign operator ： 对其进行了解释，详细阅读

陈硕github/muduo : Singleton.h 的实现中对其对copy-ctor/assign operator进行禁用，利用继承noncopyable，代码：

class Singleton : boost::noncopyable

boost/core/noncopyable.hpp

//  Boost noncopyable.hpp header file  --------------------------------------//

//  (C) Copyright Beman Dawes 1999-2003. Distributed under the Boost
//  Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 
//  See http://www.boost.org/libs/utility for documentation.

#ifndef BOOST_CORE_NONCOPYABLE_HPP
#define BOOST_CORE_NONCOPYABLE_HPP

#include <boost/config.hpp>

namespace boost {

//  Private copy constructor and copy assignment ensure classes derived from
//  class noncopyable cannot be copied.

//  Contributed by Dave Abrahams

namespace noncopyable_  // protection from unintended ADL
{
class noncopyable
{
protected:
#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) && !defined(BOOST_NO_CXX11_NON_PUBLIC_DEFAULTED_FUNCTIONS)
BOOST_CONSTEXPR noncopyable() = default;
~noncopyable() = default;
#else
noncopyable() {}
~noncopyable() {}
#endif
#if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS)
noncopyable( const noncopyable& ) = delete;
noncopyable& operator=( const noncopyable& ) = delete;
#else
private:  // emphasize the following members are private
noncopyable( const noncopyable& );
noncopyable& operator=( const noncopyable& );
#endif
};
}

typedef noncopyable_::noncopyable noncopyable;

} // namespace boost

#endif  // BOOST_CORE_NONCOPYABLE_HPP