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copied!<p>In C++0x you have <code>template typedef</code> finally available!</p> <p><em>Disclaimer: nothing has been compiled...</em></p> <p>From Wikipedia's article:</p> <pre><code>template< typename second> using TypedefName = SomeType<OtherType, second, 5>; </code></pre> <p>which in your case would yield</p> <pre><code>template <class Type> using vector3 = vector<Type, 3>; </code></pre> <p>I can't tell you how much I craved for this ;)</p> <p>However it doesn't solve the parameters issue. As mentioned, you could try and use variadic templates here, however I am unsure as to their application in this case. The normal use is with recursive methods and you would need to throw a <code>static_assert</code> in the midst.</p> <p><em>Edited</em> to take the comments into account.</p> <pre><code>template <class Type, size_t Size> class vector { public: template <class... Args> vector(Args... args): data({args...}) { // Necessary only if you wish to ensure that the exact number of args // is passed, otherwise there could be less than requested BOOST_MPL_ASSERT_RELATION(sizeof...(Args), ==, Size); } private: T data[Size]; }; </code></pre> <p>Another possibility that is already available is to combine Preprocessor generation with <code>boost::enable_if</code>.</p> <pre><code>template <class Type, size_t Size> class vector { public: vector(Type a0, typename boost::enable_if_c< Size == 1 >::type* = 0); vector(Type a0, Type a1, typename boost::enable_if_c< Size == 2 >::type* = 0); // ... }; </code></pre> <p>Using Boost.Preprocessor for the generation makes this easier.</p> <pre><code>BOOST_PP_REPEAT(MAX_COUNT, CONSTRUCTOR_MACRO, ~); // where MAX_COUNT is defined to the maximum size you wish // and CONSTRUCTOR_MACRO actually generates the constructor #define CONSTRUCTOR_MACRO(z, n, data) \ vector( \ BOOST_PP_ENUM_PARAMS(n, Type a), \ typename boost::enable_if_c< Size == n >::type* = 0 \ ); </code></pre> <p>The implementation of the constructor is left as an exercise for the reader. It's another call to <code>BOOST_PP_REPEAT</code>.</p> <p>As you can see, it soon gets ugly, so you'll be better off if you can use the variadic template version.</p>

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