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POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
 

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  1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
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    <p>I have this code (simplified from a more complex version):</p> <pre><code>template &lt;class... A1&gt; class Test { public: template &lt;class... A2&gt; void print (void(*function)(A2...,A1...)) { } }; void test_print (int a, float b, double c) { } int main () { Test&lt;float,double&gt; test; test.print&lt;int&gt; (&amp;test_print); } </code></pre> <p>If I compile it on GCC 4.6.3 using <code>g++ -std=c++0x filename.cpp</code> it compiles fine however on clang 3.0 using <code>clang++ -std=c++0x filename.cpp</code> it throws the following error:</p> <pre><code>filename.cpp:14:10: error: no matching member function for call to 'print' test.print&lt;int&gt; (&amp;test_print); ~~~~~^~~~~~~~~~ filename.cpp:3:33: note: candidate template ignored: failed template argument deduction template &lt;class... A2&gt; void print (void(*function)(A2...,A1...)) { ^ 1 error generated. </code></pre> <p>On GCC 4.7.2 there is also an error:</p> <pre><code>filename.cpp: In function 'int main()': filename.cpp:14:33: error: no matching function for call to 'Test&lt;float, double&gt;::print(void (*)(int, float, double))' filename.cpp:14:33: note: candidate is: filename.cpp:3:33: note: template&lt;class ... A2&gt; void Test::print(void (*)(A2 ..., A1 ...)) [with A2 = {A2 ...}; A1 = {float, double}] filename.cpp:3:33: note: template argument deduction/substitution failed: filename.cpp:14:33: note: mismatched types 'float' and 'int' </code></pre> <p>Now the question is: why is it failing or what am I doing wrong?</p>
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      1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
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    2. VO
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      1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
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      1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
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    1. CODid you try removing the `<int>`? C++ uses template type deduction where possible.
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      1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
      1. USleemes
    2. COg++ 4.7 error message: http://ideone.com/qwSKJl There seems to be a problem with the argument ordering.
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      1. POVariadic template code compiles on GCC 4.6 but not on clang or GCC 4.7
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    3. CO@leemes: I tried and it didn't help
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      1. USeyelash
 

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