Flibcpp is built using modern CMake, and it has no external dependencies. This makes installation and usage quite simple as long as you have a relatively recent software stack with a Fortran and compatible C++ compiler.


  1. Download and install CMake if it’s not already on your system. It is highly recommended to use a package manager such as Homebrew for Mac or YUM for Red Hat Linux.
  2. Download the Flibcpp source code from GitHub if you haven’t already.
  3. Create a new build directory (for example purposes, create a subdirectory named build inside your downloaded source directory) and cd to it.
  4. Run CMake: cmake ..
  5. Make and install (by default it will install to /usr/local): make install.

By default, Flibcpp builds shared libraries. Add the CMake argument -DBUILD_SHARED_LIBS:BOOL=OFF to build static libraries.

Downstream usage as a library

The Flibcpp library is most easily used when your downstream app is built with CMake. It should require a single line to initialize:

find_package(Flibcpp REQUIRED CONFIG)

and a single line to link against your app or library:

target_link_libraries(example_backend Flibcpp::flc_random Flibcpp::flc_algorithm)

If your installation prefix for Flibcpp is a system default path (such as /usr/local) or in your $CMAKE_PREFIX_PATH environment variable, it should automatically find the necessary CMake configure file.

An example Fortran application that depends only on Flibcpp is available on Github.

If you’re using a simple standalone Makefile to build your Fortran code, you will have to inform the compiler of the proper include path, library path, and library names. Depending on your system configuration, you might have to also explicitly link your app against the compiler’s C++ standard libraries using -lstdc++.

Downstream usage as a component

Flibcpp’s SWIG interface files can be used with your Fortran-accessible C++ project to seamlessly integrate the Flibcpp Fortran wrapper code with yours. To start, you must have the latest version of the SWIG+Fortran tool installed on your machine: the version of SWIG used by your installation of Flibcpp must match the version used by your downstream library/app. When you build Flibcpp for downstream SWIG usage, you must configure using cmake -DFLIBCPP_USE_SWIG=ON ... This will cause the SWIG interface files to be installed to ${CMAKE_PREFIX_PATH}/include to make them available downstream. Finally, in your downstream SWIG interface code, instead of calling %import <flc.i> you must use %include <import_flc.i>. This is necessary to inject function declarations and other internal macros into your wrapper code.

At that point, all you have to do is (for example) %import <flc_vector> to allow std::vector<double> in your library headers to be wrapped by Flibcpp’s VectorReal8 Fortran proxy derived type.

An example C++/Fortran library that integrates with Flibcpp will be made available on Github.


If you are interested in extending the capabilities of Flibcpp, you will need the latest version of the SWIG+Fortran tool installed on your machine. When configuring CMake, you will want to configure using cmake -DFLIBCPP_DEV=ON .. to enable tests and documentation. Tests, examples, and documentation can be independently enabled using the FLIBCPP_BUILD_TESTS, FLIBCPP_BUILD_EXAMPLES, and FLIBCPP_BUILD_DOCS options.