json VS C++ Format

I have not done a "desktop" program in 25+ years and never using C++ (or C), since then I'm mostly a web developer (PHP,Elixir, JS, Kotlin etc).

I'm currently doing a C++ audio plugin with the Juce framework.

This website has been a good resource, alongside https://www.learncpp.com

But I was actually close to give up before using those two things:

- https://github.com/nlohmann/json : my plugin use a json api backend and the Juce json implementation is atrocious (apparently because of being born in previous c++ version), but this library is GREAT.

- ChatGPT 4. I'm not sure I would have "succeeded" without it, at least not in a reasonable time frame. ChatGPT 3.5 is slow and does not give good results for my use case but 4 is impressive. And I use in a very dumb way, just posing question in the web UI. I probably could have it directly in MSVC?

Also I must say, for all its flaws, I have a renewed appreciation for doing UI on the web ;)

https://github.com/nlohmann/json works well for me

cmake_minimum_required(VERSION 3.15) project(xrpc++ DESCRIPTION "C++ AT Protocol XRPC library" VERSION 1.0.0 LANGUAGES CXX) include(FetchContent) FetchContent_Declare(cpr GIT_REPOSITORY https://github.com/libcpr/cpr.git GIT_TAG 2553fc41450301cd09a9271c8d2c3e0cf3546b73) # The commit hash for 1.10.x. Replace with the latest from: https://github.com/libcpr/cpr/releases FetchContent_MakeAvailable(cpr) FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz) FetchContent_MakeAvailable(json) add_library(${PROJECT_NAME} SHARED src/lexicon.cpp src/xrpc.cpp ) target_link_libraries(${PROJECT_NAME} PRIVATE cpr::cpr) target_link_libraries(${PROJECT_NAME} PRIVATE nlohmann_json::nlohmann_json) set_target_properties(${PROJECT_NAME} PROPERTIES VERSION ${PROJECT_VERSION}) set_target_properties(${PROJECT_NAME} PROPERTIES SOVERSION 1) target_include_directories(${PROJECT_NAME} PUBLIC include) set(CMAKE_BUILD_TYPE debug)

FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz) FetchContent_MakeAvailable(json)

Here is one popular C++ library (nlohmann/json) removing its use.

Before going into binary serialization I suggest you to get comfortable with serialization to text. You can try to write your data to text files and read them in again. Then after you get an idea of how this works you can try to use a library that writes to XML or json, e.g. nlohmann json

Download the single header file json.hpp from https://github.com/nlohmann/json/releases and place it in your project directory or an include directory.

Exemple of a JSON library: https://github.com/nlohmann/json (For XML, there's tinyxml)

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).