Boost C++ Libraries: Ticket #3298: Iterating over a map fails to compile with MSVC 9 (works with CYGWIN GCC 4.3.2)

attachment set

Wed, 29 Jul 2009 05:02:17 GMT

attachment → join_map_test.cpp

Example code that compiles with CYGWIN GCC 4.3.2 but now MSVC 9

Marshall Galbraith — Wed, 29 Jul 2009 14:09:09 GMT

First I want to acknowledge that I am an MPL novice, and am still learning the ropes of this extremely useful library. I have attached an updated example of the problem. This implementation takes better advantage of the tools provided in the mpl library.

I have two template meta functions defined in this example which joins two maps, MapL and MapR. The first function, join_maps_1, generates a new copy of the joint maps using copy and joint_view. If I understand things correctly, this requires size<MapL> + size<MapR> instantiations. This version seems to work without problems.

The second function, join_maps_2, inserts MapR into MapL using copy<>. It should require size<MapL> instantiations. However, if the resulting map is passed to for_each<>, the code fails to compile with MSVC 9 if a key has been erase from MapL.

attachment set

Marshall Galbraith — Wed, 29 Jul 2009 14:10:15 GMT

attachment → join_map_test_2.cpp

Updated example using MPL functions to join maps

Steven Watanabe — Sat, 22 Aug 2009 15:47:11 GMT

This sounds like a result of #2042. Does the patch there fix your problem?

status changed; resolution set

Marshall Galbraith — Sat, 22 Aug 2009 19:10:25 GMT

status new → closed
resolution → duplicate

This patch did indeed resolve the problem. I apologize for not discovering it on my own.

Is there a reason why the patch has not made it into the main repository?

Steven Watanabe — Sat, 22 Aug 2009 19:21:24 GMT

Replying to Marshall Galbraith:

Is there a reason why the patch has not made it into the main repository?

I'll try to get it in soon, but it's probably too late for 1.40.

Aleksey Gurtovoy — Mon, 24 Aug 2009 04:22:47 GMT

Replying to steven_watanabe:

Replying to Marshall Galbraith:

Is there a reason why the patch has not made it into the main repository?

I'll try to get it in soon, but it's probably too late for 1.40.

I've just merged Steven's fix to the release branch, so it should make it to 1.40 after all.