This document outlines the process of installing a JSON parser in Visual Studio C++ using the vcpkg package manager. It explains prerequisites, installation commands, and examples of using the nlohmann JSON library for parsing and serializing JSON data. Additional resources and examples are provided to assist users with the installation and implementation process.

1. [5분 따라하기]
비주얼 스튜디오 C++에서 JSON
파서 설치하기
박재호(jrogue@gmail.com)

2. 참고 자료
• <컴퓨터 vs 책> 블로그
• http://jhrogue.blogspot.com/
• OKdevTV 유튜브 방송
• 오늘자 방송
• https://www.youtube.com/watch?v=KH3mirEkZKU&list=PLdntWJk2tJPLKNNYBVCxn
de2PEB6dzbSL&index=14
• 5분 따라하기 리스트:
• https://www.youtube.com/playlist?list=PLdntWJk2tJPLKNNYBVCxnde2PEB6dzbSL
• 슬라이드 셰어
• https://www.slideshare.net/jrogue/presentations
• ASCIINEMA
• https://asciinema.org/~jrogue

3. 선행 조건
• Visual Studio에 영문 언어팩 설치

4. 오늘 소개할 내용
• 자바스크립트와 파이썬과는 달리 C/++에서는 JSON을 언어 차
원에서 지원하지 않음
• 이런 상황에서 비주얼 스튜디오에서 C++ 프로그램을 개발할
때 어떻게 해야할까?

5. 패키지로 설치하는 방법
• vcpkg!
• https://docs.microsoft.com/ko-kr/cpp/build/vcpkg?view=vs-2019
• C++용 명령행 패키지 관리자
• 교차 플랫폼 지원: 윈도우, 리눅스, MacOS X
• 윈도우 카탈로그에 등록된 경우 소스 코드를 다운로드해서 빌드 → 컴
파일러 버전 문제 해소

6. 설치
• $ git clone https://github.com/Microsoft/vcpkg.git
• $ cd vcpkg
• $ ./bootstrap-vcpkg.sh
• $ ./vcpkg integrate install
• $ ./vcpkg search | grep json
• $ ./vcpkg install nlohmann-json

7. 실행 결과(예시)
$ git clone https://github.com/Microsoft/vcpkg.git
Cloning into 'vcpkg'...
remote: Enumerating objects: 1, done.
remote: Counting objects: 100% (1/1), done.
remote: Total 86762 (delta 0), reused 0 (delta 0), pack-reused
86761
Receiving objects: 100% (86762/86762), 25.61 MiB | 8.41 MiB/s,
done.
Resolving deltas: 100% (53902/53902), done.
Updating files: 100% (5288/5288), done.
$ ./bootstrap-vcpkg.sh
Building vcpkg.exe ...
pch.cpp
archives.cpp
checks.cpp
chrono.cpp
...
vcpkgpaths.cpp
versiont.cpp
visualstudio.cpp
vcpkg.cpp
...
Building vcpkg.exe... done.
$ ./vcpkg integrate install
Applied user-wide integration for this vcpkg root.
All MSBuild C++ projects can now #include any installed libraries.
Linking will be handled automatically.
Installing new libraries will make them instantly available.
CMake projects should use: "-
DCMAKE_TOOLCHAIN_FILE=C:/Users/jaypark/vcpkg/scripts/buildsystems/vcpkg.
cmake"

8. 실행 결과(예시)
$ ./vcpkg search | grep json
arrow[json] JSON file support
bitserializer[cpprestjson-archive] Module for support JSON (implementation based on the CppRestSDK library)
bitserializer[rapidjson-archive] Module for support JSON (implementation based on the RapidJson library)
bitserializer-cpp... alias Deprecated alias for bitserializer-cpprestjson
bitserializer-rap... alias Deprecated alias for bitserializer-rapidjson
cjson 2019-11-30-1 Ultralightweight JSON parser in ANSI C
cjson[utils] Enable building the cJSON_Utils library
json-c 2019-09-10 A JSON implementation in C
json-dto 0.2.9.2 A small header-only library for converting data between json representation an...
json-schema-valid... 2.1.0 This is a C++ library for validating JSON documents based on a JSON Schema. Th...
json-spirit 4.1.0-1 json parser using boost library
json11 2017-06-20-2 json11 is a tiny JSON library for C++11, providing JSON parsing and serializat...
json5-parser 1.0.0-1 An enhancement of the JSON Spirit C++ library to understand json5.
jsoncons 0.155.1 A C++, header-only library for constructing JSON and JSON-like text and binary...
jsoncpp 1.9.2 jsoncpp is an implementation of a JSON reader and writer in C++. JSON (JavaScr...
jsonnet 0.14.0-1 Jsonnet - The data templating language
jwt-cpp 0.4.0 A header only library for creating and validating json web tokens in c++
nlohmann-json 3.9.1 JSON for Modern C++
parson 2019-07-11 a lighweight json library written in C
picojson 1.3.0-1 A header-file-only, JSON parser serializer in C++.
rapidjson 2020-02-08 A fast JSON parser/generator for C++ with both SAX/DOM style API <http://rapid...
sajson 2018-09-21 Lightweight, extremely high-performance JSON parser for C++11
simdjson 0.4.6 A extremely fast JSON library that can parse gigabytes of JSON per second
sqlite3[json1] enable JSON functionality for sqlite3
taocpp-json 2019-07-11 C++ header-only JSON library
valijson 2018-11-17-1 Header-only C++ library for JSON Schema validation

9. 실행 결과(예시)
$ ./vcpkg install nlohmann-json
Computing installation plan...
A suitable version of cmake was not found (required v3.17.2). Downloading portable cmake v3.17.2...
Downloading cmake...
https://github.com/Kitware/CMake/releases/download/v3.17.2/cmake-3.17.2-win32-x86.zip ->
C:Usersjayparkdocumentsvcpkgdownloadscmake-3.17.2-win32-x86.zip
Extracting cmake...
A suitable version of 7zip was not found (required v18.1.0). Downloading portable 7zip v18.1.0...
Downloading 7zip...
https://www.nuget.org/api/v2/package/7-Zip.CommandLine/18.1.0 -> C:Usersjayparkdocumentsvcpkgdownloads7-
zip.commandline.18.1.0.nupkg
Extracting 7zip...
A suitable version of nuget was not found (required v5.5.1). Downloading portable nuget v5.5.1...
Downloading nuget...
https://dist.nuget.org/win-x86-commandline/v5.5.1/nuget.exe -> C:Usersjayparkdocumentsvcpkgdownloads22ea847d-nuget.exe
The following packages will be built and installed:
nlohmann-json[core]:x86-windows
Detecting compiler hash for triplet x86-windows...
A suitable version of powershell-core was not found (required v6.2.1). Downloading portable powershell-core v6.2.1...
Downloading powershell-core...
https://github.com/PowerShell/PowerShell/releases/download/v6.2.1/PowerShell-6.2.1-win-x86.zip ->
C:UsersjayparkvcpkgdownloadsPowerShell-6.2.1-win-x86.zip
Extracting powershell-core...

10. 실행 결과(예시)
Starting package 1/1: nlohmann-json:x86-windows
Building package nlohmann-json[core]:x86-windows...
Could not locate cached archive:
C:UsersjayparkAppDataLocalvcpkg/archives1e1e699d54ec05be35d7ea0e7c4de7a1672bd0b286.zip
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/CMakeLists.txt...
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/LICENSE.MIT...
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/nlohmann_json.natvis...
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/cmake/config.cmake.in...
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/cmake/pkg-config.pc.in...
-- Downloading https://github.com/nlohmann/json/raw/v3.9.1/cmake/nlohmann_jsonConfigVersion.cmake.in...
-- Downloading https://github.com/nlohmann/json/releases/download/v3.9.1/include.zip...
-- Extracting source C:/Users/jaypark/documents/vcpkg/downloads/nlohmann-json-v3.9.1-include.zip
-- Using source at C:/Users/jaypark/documents/vcpkg/buildtrees/nlohmann-json/3.9.1-74ced61d52.clean
-- Configuring x86-windows
-- Building x86-windows-dbg
-- Building x86-windows-rel
-- Installing: C:/Users/jaypark/documents/vcpkg/packages/nlohmann-json_x86-windows/share/nlohmann-json/copyright
-- Performing post-build validation
-- Performing post-build validation done
Stored binary cache: C:UsersjayparkAppDataLocalvcpkg/archives1e1e699d54ec05be35d7ea0e7c4de7a1672bd0b286.zip
Building package nlohmann-json[core]:x86-windows... done
Installing package nlohmann-json[core]:x86-windows...
Installing package nlohmann-json[core]:x86-windows... done
Elapsed time for package nlohmann-json:x86-windows: 12.56 s
Total elapsed time: 30.43 s
The package nlohmann-json:x86-windows provides CMake targets:
find_package(nlohmann_json CONFIG REQUIRED)
target_link_libraries(main PRIVATE nlohmann_json nlohmann_json::nlohmann_json)

11. 실제 사용(예시)
#include <nlohmann/json.hpp>
using nlohmann::json;
json j1 = json::parse(json_string); // 파싱
// 1st class data type
json j2 = {
{"pi", 3.141},
{"happy", true},
{"name", "Niels"},
{"nothing", nullptr},
{"answer", {
{"everything", 42}
}},
{"list", {1, 0, 2}},
{"object", {
{"currency", "USD"},
{"value", 42.99}
}}
};
json j3 = "{ "happy": true, "pi": 3.141 }"_json; // serialize