Hi,
I'm using boost versions 1.33.1 and 1.34.1 with gcc 4.1.2 (Linux)
and boost 1.33.1 with gcc 3.3.2 on solaris and MSVC8
I'm trying to use multi_index as a container indexed by two integers
in a class called MapEntry. The two indices represent a unique key
number "key" and a possibly non-unique timestamp "age". To make it
generic I have the data in a shared_ptr<T> in the MapEntry class
because I wanted to use the aged map functionality with many classes
in the shared_ptr:
// the tags
struct keytag { };
struct agetag { };
template <typename T>
struct MapEntry
{
.... stripped out all constructors and methods ...
int key;
int age;
private:
boost::shared_ptr<T> payload;
};
and the multi_index_container setup as a wrapper class since C++ doesn't have typedef templates
because I figured I needed that to get the "T" into the MapEntry<T> ....
template<typename T>
class AgedMap {
typedef T map_type;
public:
typedef multi_index_container<
MapEntry<T>,
indexed_by<
ordered_unique<
tag<keytag>, BOOST_MULTI_INDEX_MEMBER(MapEntry<T>, int, key) >,
ordered_non_unique<
tag<agetag>, BOOST_MULTI_INDEX_MEMBER(MapEntry<T>, int, age) >
>
> AGEDMAPTYPE;
};
and in main() I declare the container as:
AgedMap::AGEDMAPTYPE am;
and do insert, finds and erases into it.
My problem is that it seems that if I use the T template to call my flush_by_age template function :
template
void flush_by_age(MIContainer& mic, int timeout)
{
.....
which is called from main() as (note AH_ENTRY is a very simple
struct with just a single int in it and cctor/ctor/dtor for testing)
flush_by_age(am, AGELIMIT);
and use that T to define what AGE_INDEX is inside it:
// this hard coded one compiles and runs on all my platforms
// but loses the whole point of genericness
//typedef AgedMap::AGEDMAPTYPE::index<agetag>::type AGE_INDEX;
// this AGE_INDEX does not on gcc but DOES compile on MSVC8
typedef AgedMap<T>::AGEDMAPTYPE::index<agetag>::type AGE_INDEX;
I get a compiler error at the AGE_INDEX typedef in gcc 3.3.2 (solaris 10):
aged_map.cc: In function `void flush_by_age(MIContainer&, int)':
aged_map.cc:159: warning: `boost::multi_index::multi_index_container::index<agetag>::type' is implicitly a
typename
and a more verbose one on gcc 4.1.2 (Fedora 6 Linux):
aged_map.cc: In function âvoid flush_by_age(MIContainer&, int)â:
aged_map.cc:159: error: non-template 'index' used as template
aged_map.cc:159: note: use âboost::multi_index::multi_index_container,
boost::multi_index::member, mpl_::na>,
boost::multi_index::ordered_non_unique<
boost::multi_index::tag,
boost::multi_index::member, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator >::template index' to indicate that it is a template
aged_map.cc:159: error: too few template-parameter-lists
But MSVC 8 compiles it fine and it runs.
But if I hard code the class in my AGE_INDEX typedef
to "" to replace the <T> in the flush_by_age()
it compiles fine on ALL those compilers and they all run ok.
I'm wanting to find out what I can possibly do because
this would be a very useful class for since I currently have
to put the aging information in another container where
this let's me do it in one. I use unix and Windows and
on Windows the compiler must be MSVC and on unix
gcc. I tried making the typename explicit by adding
"typename" using the hint from the solaris error but that didn't help.
I'm guessing I've got some syntax typo like a missing & or const
somewhere ?
thanks,
Mark
