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copied!<p>You don't need to template the <code>friend</code> part, but you need to signify that the <code>friend</code> function is a template:</p> <pre><code>friend boost::shared_ptr<Connection> boost::make_shared<>(/* ... */); // ^^ </code></pre> <p>That works with Comeau and current GCC versions but fails with VC. Better would be the following form:</p> <pre><code>friend boost::shared_ptr<Connection> boost::make_shared<Connection>(/* ... */); </code></pre> <p>That works across multiple compilers now - i tested it on VC8, VC10, GCC 4.2, GCC 4.5 and Comeau 4.3.</p> <p>Alternatively using a qualified name to refer to a particular instance of the function template as Martin does <em>should</em> work and does with Comeau, but GCC chokes on it.</p> <p>A useful alternative that doesn't depend on the implementation details of <code>make_shared()</code> (and thus also works with <a href="https://stackoverflow.com/questions/3541632/using-make-shared-with-a-protected-constructor-abstract-interface/3541733#3541733">VC10s TR1 implementation</a>) is to use the <a href="https://stackoverflow.com/questions/3220009/is-this-key-oriented-access-protection-pattern-a-known-idiom">pass-key-idiom</a> for access-protection of the constructor and to befriend the <code>create()</code> function instead, e.g.:</p> <pre><code>class Connection { // ... public: class Key { friend boost::shared_ptr<Connection> create(const ConnectionManagerPtr&, const std::string&); Key() {} }; Connection(const ConnectionManagerPtr&, const std::string&, const Key&); }; boost::shared_ptr<Connection> create(const ConnectionManagerPtr& p, const std::string& s) { return boost::make_shared<Connection>(p, s, Connection::Key()); } </code></pre>

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