# [`crany`][] **C**oncept-based **R**elaying **Any** C++14 type. For a usage example, see `tests/crany.cpp`. For a diagram visualizing the implementation, see `doc/crany.dot.png`. [`crany`]: https://git.rcrnstn.net/rcrnstn/crany ## References The references below focus on the timeline and online resources. This work builds on that of many others: - Chris Cleeland, Douglas Schmidt, Timothy Harrison - External Polymorphism - 1996, Proceedings of the 3rd Pattern Languages of Programming Conference, [paper](https://www.dre.vanderbilt.edu/~schmidt/PDF/C++-EP.pdf) - Kevlin Henney - Valued Conversions - 2000, C++ Report, [paper](https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.374.2252&rep=rep1&type=pdf) - Sean Parent - Runtime Concepts: Generic Programming and Runtime Polymorphism - Unpublished, [paper](https://stlab.cc/legacy/runtime-concepts.html) - Concept-Based Runtime Polymorphism - 2007, BoostCon, [slides](https://stlab.cc/legacy/figures/Boost_poly.pdf) - Value Semantics and Concept-based Polymorphism - 2012, C++Now, [talk](https://www.youtube.com/watch?v=_BpMYeUFXv8), [slides](https://sean-parent.stlab.cc/papers-and-presentations/#value-semantics-and-concept-based-polymorphism) - Inheritance Is The Base Class of Evil - 2013, GoingNative, [talk](https://www.youtube.com/watch?v=bIhUE5uUFOA), [slides](https://sean-parent.stlab.cc/papers-and-presentations/#inheritance-is-the-base-class-of-evil) - Better Code: Runtime Polymorphism - 2017, NDC, [talk](https://www.youtube.com/watch?v=QGcVXgEVMJg), [slides](https://sean-parent.stlab.cc/papers-and-presentations/#better-code-runtime-polymorphism) - Louis Dionne - Runtime Polymorphism: Back to the Basics - 2017, CppCon, [talk](https://www.youtube.com/watch?v=gVGtNFg4ay0), [slides](https://ldionne.com/cppcon-2017-runtime-polymorphism) - 2018, ACCU, [talk](https://www.youtube.com/watch?v=H8lFldGvt9w), [slides](https://ldionne.com/accu-2018-runtime-polymorphism) - 2018, C++Now, [talk](https://www.youtube.com/watch?v=OtU51Ytfe04), [slides](https://ldionne.com/cppnow-2018-runtime-polymorphism) Other related work: - Zach Laine - Pragmatic Type Erasure: Solving OOP Problems w/ Elegant Design Pattern - 2014, CppCon, [talk](https://www.youtube.com/watch?v=0I0FD3N5cgM) - Sy Brand - Dynamic Polymorphism with Metaclasses and Code Injection - 2020, CppCon, [talk](https://www.youtube.com/watch?v=8c6BAQcYF_E) - Klaus Igelberger - Breaking Dependencies: Type Erasure - A Design Analysis - 2021, CppCon, [talk](https://www.youtube.com/watch?v=4eeESJQk-mw&t=23m26s) Related projects: - Adobe's [Poly](https://stlab.adobe.com/group__poly__related.html) (of which Sean Parent was a principal contributor) - Louis Dionne's [Dyno](https://github.com/ldionne/dyno) - Facebook's [Folly Poly](https://github.com/facebook/folly/blob/main/folly/docs/Poly.md) Related patterns: - Adapter pattern - [Wikipedia](https://en.wikipedia.org/wiki/Adapter_pattern) - [GoF Design Patterns](https://en.wikipedia.org/wiki/Design_Patterns) - Decorator pattern - [Wikipedia](https://en.wikipedia.org/wiki/Decorator_pattern) - [GoF Design Patterns](https://en.wikipedia.org/wiki/Design_Patterns) - External Polymorphism pattern - [WikiWikiWeb](https://wiki.c2.com/?ExternalPolymorphism) ## Build system This project supports [CMake][] and uses [`cmake-common`][]. There are several ways to use it in other CMake-based projects: - With [`find_package`][]: ([Package][] and) [install][] it on the system. - With [`add_subdirectory`][]: Bundle it. - With [`FetchContent`][]: Download it as part of the CMake configure step. - With [`cmake-common`][]: Use any of the above methods through a simplified interface. As usual, use [`add_dependencies`][] or [`target_link_libraries`][] (or `cmake-common`'s `DEPENDENCIES_*`) to declare the dependency. [CMake]: https://cmake.org [`cmake-common`]: https://git.rcrnstn.net/rcrnstn/cmake-common [`FetchContent`]: https://cmake.org/cmake/help/v3.14/module/FetchContent.html [`add_subdirectory`]: https://cmake.org/cmake/help/v3.14/command/add_subdirectory.html [`find_package`]: https://cmake.org/cmake/help/v3.14/command/find_package.html [Package]: #Package [Install]: #Install [`add_dependencies`]: https://cmake.org/cmake/help/v3.14/command/add_dependencies.html [`target_link_libraries`]: https://cmake.org/cmake/help/v3.14/command/target_link_libraries.html ### Configure and generate To configure and generate a build tree, use `cmake`: ```sh cmake -B _build ``` To set the build type, pass e.g. `-D`[`CMAKE_BUILD_TYPE`][]`=Release`. [`cmake`]: https://cmake.org/cmake/help/v3.14/manual/cmake.1.html#generate-a-project-buildsystem [`CMAKE_BUILD_TYPE`]: https://cmake.org/cmake/help/v3.14/variable/CMAKE_BUILD_TYPE.html ### Build To build, use [`cmake --build`][]: ```sh cmake --build _build ``` To disable building tests, pass `-D`[`BUILD_TESTING`][]`=OFF`. [`cmake --build`]: https://cmake.org/cmake/help/v3.14/manual/cmake.1.html#build-a-project [`BUILD_TESTING`]: https://cmake.org/cmake/help/v3.14/module/CTest.html ### Test To run tests, use [`ctest`][]: ```sh (cd _build && ctest) ``` To show output from failing tests, pass `--output-on-failure`. To show output from all tests, pass `--verbose`. [`ctest`]: https://cmake.org/cmake/help/v3.14/manual/ctest.1.html ### Package To package, use [`cpack`][]: ```sh (cd _build && cpack) ``` [`cpack`]: https://cmake.org/cmake/help/v3.14/manual/cpack.1.html ### Install To install onto the current system, use [`cmake --install`][]: ```sh cmake --install _build ``` To set the prefix, pass e.g. `-D`[`CMAKE_INSTALL_PREFIX`][]`="$HOME/.local"`. [`cmake --install`]: https://cmake.org/cmake/help/v3.14/manual/cmake.1.html#install-a-project [`CMAKE_INSTALL_PREFIX`]: https://cmake.org/cmake/help/v3.14/variable/CMAKE_INSTALL_PREFIX.html ## License Licensed under the [ISC License][] unless otherwise noted, see the [`LICENSE`][] file. [ISC License]: https://choosealicense.com/licenses/isc [`LICENSE`]: LICENSE