C++ Format VS Better Enums

Continuation passing monads form the basis of a perfectly valid and usable software architecture and programming pattern.

In the case of ostream and operator<<, this pattern reduces the number of intermediate objects that would otherwise be constructed.

If you object to iostream on religious or stylistic grounds, there's always fmt which is more like Go or Python string interpolation.[0]

0. https://fmt.dev

GitHub repo: fmtlib/fmt

cmake_minimum_required(VERSION 3.5) project(knn_cpp CXX) # Set up C++ version and properties include(CheckIncludeFileCXX) check_include_file_cxx(any HAS_ANY) check_include_file_cxx(string_view HAS_STRING_VIEW) check_include_file_cxx(coroutine HAS_COROUTINE) set(CMAKE_CXX_STANDARD 20) set(CMAKE_BUILD_TYPE Debug) set(CMAKE_CXX_STANDARD_REQUIRED ON) set(CMAKE_CXX_EXTENSIONS OFF) # Copy data file to build directory file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/iris.data DESTINATION ${CMAKE_CURRENT_BINARY_DIR}) # Download library usinng FetchContent include(FetchContent) FetchContent_Declare(matplotplusplus GIT_REPOSITORY https://github.com/alandefreitas/matplotplusplus GIT_TAG origin/master) FetchContent_GetProperties(matplotplusplus) if(NOT matplotplusplus_POPULATED) FetchContent_Populate(matplotplusplus) add_subdirectory(${matplotplusplus_SOURCE_DIR} ${matplotplusplus_BINARY_DIR} EXCLUDE_FROM_ALL) endif() FetchContent_Declare( fmt GIT_REPOSITORY https://github.com/fmtlib/fmt.git GIT_TAG 7.1.3 # Adjust the version as needed ) FetchContent_MakeAvailable(fmt) # Add executable and link project libraries and folders add_executable(${PROJECT_NAME} main.cc) target_link_libraries(${PROJECT_NAME} PUBLIC matplot fmt::fmt) aux_source_directory(lib LIB_SRC) target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}) target_sources(${PROJECT_NAME} PRIVATE ${LIB_SRC}) add_subdirectory(tests)

Good catch, thanks! Fixed now. This explains why the difference was kinda low compared to another benchmark: https://github.com/fmtlib/fmt?tab=readme-ov-file#compile-tim....

> This is from C++23, right?

std::println is, yes.

> I wonder how available this is within compilers

https://en.cppreference.com/w/cpp/compiler_support says clang, gcc, and msvc all support it, though I don't know how recent those versions are off the top of my head.

In my understanding, with this specific feature, if you want a polyfill for older compilers, or to use some more cutting-edge features that haven't been standardized yet, https://github.com/fmtlib/fmt is available to you.

{fmt} has internal buffering but it's not yet exposed to users. There is a feature request for it: https://github.com/fmtlib/fmt/issues/2354. FILE buffering is not too bad but it can be easily optimized: https://www.zverovich.net/2020/08/04/optimal-file-buffer-siz....

Automatic use of operator<< when that exists was present in fmt until version 9.0.0. In version 9 you could use FMT_DEPRECATED_OSTREAM to opt in the old behaviour, but this too was removed in version 10.0.0. Now there is no way to automatically use operator<<.

You can install it https://github.com/fmtlib/fmt

Additionally, if you like low level stuff, check out libfmt (https://github.com/fmtlib/fmt) - not a big project, not difficult to understand. Or something like simdjson (https://github.com/simdjson/simdjson).

I really like better_enums instead of magic_enums. There’s no limit on enum size with it: http://aantron.github.io/better-enums/

It was heavily used at a former employer of mine, so definitely a solid production-ready solution.

IIRC I then switched to another library doing the same stuff: https://github.com/aantron/better-enums It is not as magical, as it uses a special macro to define the enum, using dedicated syntax. So it only works for enums you yourself define. However, it did work a lot better for me with enums with huge values.

I can't keep up! First we have better enum, then some guy at a conference says we have to use wise enum instead, and now you speak of magic enum!

If you need a laugh today, look at Better Enums library for C++. If you thought moving from C to C++ would let you leave macros behind, think again! Enums in C++ still suck (a bit less than in C though), so someone built a library to help with that. And it's built on macros. So you can only have 64 entries per enum. And the library's code is barely readable.