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    <pre><code>class Sample { std::vector&lt;int&gt; v; private: struct Mut; }; struct Sample::Mut { boost::mutex mut_; }; </code></pre> <p>or</p> <pre><code>class Sample { std::vector&lt;int&gt; v; public: boost::shared_ptr&lt;boost::mutex&gt; mutt; Sample() : mutt(new boost::mutex) {} }; </code></pre> <p>now you can refer to the <code>boost::mutex</code> of this sample in other objects providing an access to mutex wrapper, or maybe directly initializing these objects with copy of <code>Mut</code> structure or <code>boost::shared_ptr</code>. <code>boost::shared_ptr</code> is <em>copyable</em> and all its copies <strong>will share</strong> given mutex.</p> <hr> <blockquote> <p>And why can't mutexes be copied?</p> </blockquote> <p>Because mutex is <em>noncopyable</em>. This is it derives from <code>boost::noncopyable</code>:</p> <pre><code>#include &lt;boost/thread/mutex.hpp&gt; class mutex: boost::noncopyable { </code></pre> <blockquote> <p>Class noncopyable is a base class. Derive your own class from noncopyable when you want to prohibit copy construction and copy assignment.</p> </blockquote> <p>You don't need their copy in fact because it would be useless, but rather you want to share same instance in many objects and refer to a single mutex which guards access to single resource. </p> <p>from <code>&lt;boost/noncopyable.hpp&gt;</code> :</p> <pre><code>// 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: #ifndef BOOST_NO_DEFAULTED_FUNCTIONS BOOST_CONSTEXPR noncopyable() = default; ~noncopyable() = default; #else noncopyable() {} ~noncopyable() {} #endif #ifndef BOOST_NO_DELETED_FUNCTIONS noncopyable( const noncopyable&amp; ) = delete; noncopyable&amp; operator=( const noncopyable&amp; ) = delete; #else private: // emphasize the following members are private noncopyable( const noncopyable&amp; ); noncopyable&amp; operator=( const noncopyable&amp; ); #endif }; } typedef noncopyable_::noncopyable noncopyable; </code></pre>
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    1. POTips to share container between 2 objects?
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    1. COI'm not sure how the implementation of `noncopyable` explains *why* a mutex has been deliberately made non-copyable.
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    2. CO@DyP you can [ask](http://stackoverflow.com/questions/ask) such question on SO, here it is only to emphasize that copy constructor and copy assignment members are private
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    3. COand I always prefer to show some real code than just speculate (or mull out the theory). here you can see that indeed constructor of mutex is private
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