[Boost-users] [multi_index] FYI: Experiences with the Boost.MulitIndex container

From: Jochen Hammann (jochen.hammann_at_[hidden])
Date: 2005-02-17 04:02:08

Hi,

I am using the Boost MultiIndex container in conjunction with the Microsoft Visual C++ 7.1 compiler. 
I encountered an runtime exception during some tests of my application. I made the mistake, that I 
tried to construct an index as a separate object instead of using a reference to the respective index.

The MultiIndex documentation highlights this issue:

"Note that get returns a reference to the index, and not an index object. Indices cannot be 
constructed as separate objects from the container they belong to, so the following

// Wrong: we forgot the & after employee_set::nth_index<1>::type
const employee_set::nth_index<1>::type name_index=es.get<1>();

does not compile, since it is trying to construct the index object name_index. This is a common 
source of errors in user code."

I could reproduce the exception by using the MultiIndex example basic.cpp from the Boost 1.32.0 
release. Unfortunately, Microsoft Visual C++ 7.1 compiles the above mentioned line without an error 
or warning. During the execution of the example an exception will be thrown while processing the 
following line:

   std::copy(i.begin(),i.end(),std::ostream_iterator<value_type>(std::cout));

within the function template print_out_by().

Regards,

    Jochen.