Re: [boost] [multi-array] compiler errors with visual studio 2012 ([e-mail])

Subject: Re: [boost] [multi-array] compiler errors with visual studio 2012 ([e-mail])
From: Dan Searles (dansearles_at_[hidden])
Date: 2013-03-27 11:03:50

>Date: Sat, 23 Mar 2013 14:12:24 +0100 (CET)
>From: nfarnsworth_at_[hidden]
>To: boost_at_[hidden]
>Subject: [boost] [multi-array] compiler errors with visual studio 2012
>Message-ID:
>    <trinity-07de36eb-bb16-4dc9-b97b-68516d068e24-1364044344811_at_3capp-webde-bs37>
>    
>Content-Type: text/plain; charset="UTF-8"
>
>
>   Hello,
>   have this c++ example which compiles with Visual Studio 2010 but with Visual
>   Studio 2012 I got this compiler errors:
>   1>------ Build started: Project: MultiArrayDemo, Configuration: Debug Win32
>   ------
>   1>  MultiArrayDemo.cpp
>   1>d:\sandbox\multiarraydemo\multiarraydemo\multiarraydemo.cpp(11):error
>   C2059: syntax error : '<'
>   1>         d:\sandbox\multiarraydemo\multiarraydemo\multiarraydemo.cpp(25)
>   : see reference to class template instantiation 'Data<T>' being compiled
>   1>d:\sandbox\multiarraydemo\multiarraydemo\multiarraydemo.cpp(11):error
>   C2238: unexpected token(s) preceding ';'
>   ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
>   The example uses the boost 1.53 version. Here is the example code:
>   #include "stdafx.h"
>   #include <boost/multi_array.hpp>
>   const int rows = 3;
>   const int cols = 5;
>   template<class T> struct Data
>   {
>    typedef boost::multi_array<T,2> data_type;
>    typedef typename data_type::array_view<1>::type view_type; //here is the
>   first error
>    typedef typename data_type::index_range range;
>    Data()
>    :A(boost::extents[rows][cols])
>    {
>      double tmp[] =
>   {1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10.0,11.0,12.0,13.0,14.0,15.0};
>      A.assign(tmp,tmp+ (rows * cols));
>    }
>    data_type A;
>   };
>   int _tmain(int argc, _TCHAR* argv[])
>   {
>
>    Data<double>* data = new Data<double>();
>    Data<double>::view_type myView =
>   data->A[boost::indices[0][Data<double>::range()]];
>    delete data;
>     return 0;
>   }
>   Does anybody know how to solve this problem?
>   Best regards and thank you in advance
>   Niklas

According to Microsoft, the code is non-conformant. Visual Studio 2010 allowed the
code to be compiled, but 2012 tightened the requirement. See:

http://msdn.microsoft.com/en-us/library/bb531344.aspx
(Second point, "Use the template keyword...", but note that they highlighted the wrong keyword).

The simple fix is to add the keyword 'template':

    typedef typename data_type::template array_view<1>::type view_type; //here is the  first error

Dan Searles