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POC++ template specialization for map-like types
 

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    <p>I want to define a generic function for printing contents of <code>std::map</code> like types. My initial attempt is a function like this:</p> <pre><code>template &lt;class K, class V&gt; inline void PrintCollection(const std::map&lt;K,V&gt;&amp; map, const char* separator="\n", const char* arrow="-&gt;", const char* optcstr="") { typedef typename std::map&lt;K,V&gt;::const_iterator iter_type; std::cout &lt;&lt; optcstr; for (iter_type begin = map.begin(), it = begin, end = map.end(); it != end; ++it) { if (it != begin) { std::cout &lt;&lt; separator; } std::cout &lt;&lt; it-&gt;first &lt;&lt; arrow &lt;&lt; it-&gt;second; } std::cout &lt;&lt; std::endl; } </code></pre> <p>which works fine. When I try to generalize this function one more step, i.e. make it work for <code>std::multimap</code> type, compiler becomes angry. I tried several ways to make <code>std::map</code> generic in the function definition, such as:</p> <pre><code>template &lt;class M, class K, class V&gt; inline void PrintCollection(const M&lt;K,V&gt;&amp; map, const char* separator="\n", const char* arrow="-&gt;", const char* optcstr="") { typedef typename M&lt;K,V&gt;::const_iterator iter_type; std::cout &lt;&lt; optcstr; for (iter_type begin = map.begin(), it = begin, end = map.end(); it != end; ++it) { if (it != begin) { std::cout &lt;&lt; separator; } std::cout &lt;&lt; it-&gt;first &lt;&lt; arrow &lt;&lt; it-&gt;second; } std::cout &lt;&lt; std::endl; } </code></pre> <p>with no success.</p> <p>How can I generalize this function as I defined above?</p> <p>To be more clear, I have already a function defined for vector-like classes defined before this function. It is like</p> <pre><code>template &lt;class T&gt; inline void PrintCollection(const T&amp; collection, const char* separator="\n", const char* optcstr="") { typedef typename T::const_iterator iter_type; std::cout &lt;&lt; optcstr; for (iter_type begin = collection.begin(), it = begin, end = collection.end(); it != end; ++it) { if (it != begin) { std::cout &lt;&lt; separator; } std::cout &lt;&lt; *it; } std::cout &lt;&lt; std::endl; } </code></pre> <p>So what I want to achieve it to make this function specialized to map-like classes. I'm pretty new in C++, so I don't know the exact term for this kind of stuff. Is this called "template specialization"?</p>
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