# Reusing out of tree c++ module?
**URL:** https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332
**Category:** Usage
**Created:** [November 1, 2023, 7:48pm UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332 "2023-11-01T19:48:52Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Glad](https://discourse.cmake.org/u/Glad)
#### Post date: [November 1, 2023, 7:48pm UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/1 "2023-11-01T19:48:52Z")
Hi,
Waiting for the 3.28 official release, what would importing a module from another directory look like ?
The [helloword example](https://www.kitware.com/import-cmake-the-experiment-is-over) has foo.cxx in the same dir, but sooner or later we will end up with modules in some directories and project located elsewhere calling them.
Main proj dir
----- CMakeLists.txt
----- main.cpp ← import module in that source
Module dir
----- CMakeLists.txt
----- mod.cxx ← export module from that source
----- build/
A helloworld with that scenario would be nice 🙂
Thanks
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### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [November 3, 2023, 2:15am UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/2 "2023-11-03T02:15:04Z")
There are examples in the test suite. To get this to work, you’ll need:
- a `Ninja` generator (Visual Studio doesn’t provide the needed information for CMake to do what is needed at build time);
- a `CXX_MODULES_DIRECTORY` argument to the `export` and/or `install(EXPORT)` calls to generate the needed information;
- consumption from a `Ninja` build (Visual Studio can support it, CMake just needs to do a bit more to get it all correct).
Once that is done, you just link the target as normal.
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### Author:  [@Glad](https://discourse.cmake.org/u/Glad)
#### Post date: [November 4, 2023, 7:01am UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/3 "2023-11-04T07:01:08Z")
I missed the fact that modules are managed like static libs with a differing way to set the source.
With the examples it became clear.
Thanks,
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### Author:  [@Glad](https://discourse.cmake.org/u/Glad)
#### Post date: [November 4, 2023, 12:31pm UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/4 "2023-11-04T12:31:10Z")
The most straightforward way I could find to use multiple modules from out of tree, is to link the folders/files in the current project’s tree.
Otherwise, the experience is very verbose. Not sure if it has some complications down the road, but it is the easiest way I could find right now.
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### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [November 17, 2023, 1:29pm UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/5 "2023-11-17T13:29:10Z")
This sounds like a hack and not something likely to work long-term or scale well. Why is using the imported targets not sufficient?
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### Author:  [@Glad](https://discourse.cmake.org/u/Glad)
#### Post date: [November 17, 2023, 2:02pm UTC](https://discourse.cmake.org/t/reusing-out-of-tree-c-module/9332/6 "2023-11-17T14:02:03Z")
You are right, forgot to update, but I ended doing it the usual way, with specifying the other folders in the current CMake.
Thanks Ben,