Workflows

This section summarizes some possible layouts and workflows when using Conan together with other tools as an end-user for installing and consuming existing packages. To create your own packages, please refer to Creating Packages.

Whether you are working on a single configuration or a multi configuration project, in both cases, the recommended approach is to have a conanfile (either .py or .txt) at the root of your project.

Single configuration

When working with a single configuration, your conanfile will be quite simple as shown in the examples and tutorials we have used so far in this user guide. For example, in Getting started, we showed how you can run the conan install .. command inside the build folder resulting in the conaninfo.txt and conanbuildinfo.cmake files being generated there too. Note that the build folder is temporary, so you should exclude it from version control to exclude these temporary files.

Out-of-source builds are also supported. Let’s look at a simple example:

$ git clone https://github.com/memsharded/example-poco-timer
$ conan install ./example-poco-timer --install-folder=example-poco-build

This will result in the following layout:

example-poco-build
    conaninfo.txt
    conanbuildinfo.txt
    conanbuildinfo.cmake
example-poco-timer
    CMakeLists.txt  # If using cmake, but can be Makefile, sln...
    LICENSE
    README.md
    conanfile.txt
    timer.cpp

Now you are ready to build:

$ cd example-poco-build
$ cmake ../example-poco-timer -G "Visual Studio 15 Win64"  # or other generator
$ cmake --build . --config Release
$ ./bin/timer

We have created a separate build configuration of the project without affecting the original source directory in any way. The benefit is that we can freely experiment with the configuration: We can clear the build folder and build another. For example, changing the build type to Debug:

$ rm -rf *
$ conan install ../example-poco-timer -s build_type=Debug
$ cmake ../example-poco-timer -G "Visual Studio 15 Win64"
$ cmake --build . --config Debug
$ ./bin/timer

Multi configuration

You can also manage different configurations, whether in-source or out of source, and switch between them without having to re-issue the conan install command (Note however, that even if you did have to run conan install again, since subsequent runs use the same parameters, they would be very fast since packages would already have been installed in the local cache rather than in the project)

$ git clone https://github.com/memsharded/example-poco-timer
$ conan install example-poco-timer -s build_type=Debug -if example-poco-build/debug
$ conan install example-poco-timer -s build_type=Release -if example-poco-build/release

$ cd example-poco-build/debug && cmake ../../example-poco-timer -G "Visual Studio 15 Win64" && cd ../..
$ cd example-poco-build/release && cmake ../../example-poco-timer -G "Visual Studio 15 Win64" && cd ../..

Note

You can either use the --install-folder or -if flags to specify where to generate the output files, or manually create the output directory and navigate to it before executing the conan install command.

So the layout will be:

example-poco-build
  debug
      conaninfo.txt
      conanbuildinfo.txt
      conanbuildinfo.cmake
      CMakeCache.txt # and other cmake files
  release
      conaninfo.txt
      conanbuildinfo.txt
      conanbuildinfo.cmake
      CMakeCache.txt # and other cmake files
example-poco-timer
    CMakeLists.txt  # If using cmake, but can be Makefile, sln...
    LICENSE
    README.md
    conanfile.txt
    timer.cpp

Now you can switch between your build configurations in exactly the same way you do for CMake or other build systems, by moving to the folder in which the build configuration is located, because the Conan configuration files for that build configuration will also be there.

$ cd example-poco-build/debug && cmake --build . --config Debug && cd ../..
$ cd example-poco-build/release && cmake --build . --config Release && cd ../..

Note that the CMake include() of your project must be prefixed with the current cmake binary directory, otherwise it will not find the necessary file:

include(${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
conan_basic_setup()