{"id":448,"date":"2025-04-15T18:15:00","date_gmt":"2025-04-15T18:15:00","guid":{"rendered":"https:\/\/permutationcity.co.uk\/bp\/?p=448"},"modified":"2025-04-14T19:21:49","modified_gmt":"2025-04-14T19:21:49","slug":"vcpkg","status":"publish","type":"post","link":"https:\/\/permutationcity.co.uk\/bp\/2025\/04\/15\/vcpkg\/","title":{"rendered":"vcpkg"},"content":{"rendered":"\n

It’s best if you can avoid re-inventing the wheel.\nIf someone has already written the code you need then it can save a lot of time.\nAlthough you should probably make sure about\nlicences<\/a>\nbefore incorporating it.\nThat could be copy-pasting something off a web page but,\nespecially for bigger bits of code,\nfar better as a library.\nHowever, as you get more libraries and they themselves need other libraries it can get complicated.\nvcpkg<\/a>\nlets you outsource a lot of that complexity.<\/p>\n\n\n\n

The old way<\/h2>\n\n\n\n

Let’s say you want to use the C++\nfmt library<\/a>.\nThere are a variety of ways to get the library.\nPerhaps installing it on a Linux system using\nAPT<\/a>:<\/p>\n\n\n\n

apt install libfmt-dev<\/pre><\/div>\n\n\n\n
But installing on the system requires documentation or a setup script. It something that’s easy to miss when setting up a project. Maybe make use of the CMake<\/a> build system to fetch<\/a> it for you:<\/p>\n\n\n\n
include(FetchContent)\n\nFetchContent_Declare(\n    fmt\n    GIT_REPOSITORY https:\/\/github.com\/fmtlib\/fmt\n    GIT_TAG e69e5f977d458f2650bb346dadf2ad30c5320281) # 10.2.1\nFetchContent_MakeAvailable(fmt)<\/pre><\/div>\n\n\n\n
This is pretty good.\nYou just need need to run cmake and it will download and build the library.\nHowever it’s going to do that every time you run cmake which can be slow.\nThis is also a simple setup with one library and no dependencies.<\/p>\n\n\n\n
A new way<\/h2>\n\n\n\n
What you could do instead is use vcpkg.\nIt’s most useful when you have a bunch of libraries as you will need to do some\nsetup<\/a>.\nHowever after that you can create a vcpkg.json<\/code> file:<\/p>\n\n\n\n
{\n    "dependencies": [\n        "fmt"\n    ]\n}<\/pre><\/div>\n\n\n\n
If you want more packages just add them to the list.\nThere’s an extensive\npackage directory<\/a>.\nThey will be downloaded and compiled before you do your build.\nAll the artefacts will be cached so it only has to happen when you change your build setup.<\/p>\n\n\n\n
If the package you want has it’s own dependencies you don’t have to worry about it.\nvcpkg will download everything that’s needed first.\nBy default it just gets the latest available version but you can\nspecify the package version<\/a>.\nIf the library you want isn’t available or needs customisation you can even write an\noverlay port<\/a>\nto pull it in to the system yourself.<\/p>\n\n\n\n
It’s not perfect.\nEspecially if you are dealing with more advanced features like\noverlay triplets<\/a>.\nThe caching mechanism can feel a bit mysterious.\nSometimes you change the build system and suddenly it “decides” to recompile.\nIt has all the downloaded source in it’s cache but\nit will have to recompile the source.\nUnfortunately I’ve used some big libraries and been hit by long compile times.\nThat’s not too bad as a one off but it kept happening.\nI’m going to say this is more a problem of understanding when it happens rather a bug in the system.<\/p>\n\n\n\n
In the end<\/h2>\n\n\n\n
There are a lot of ways to consume libraries.\nIf you only need a few it probably doesn’t matter too much.\nHowever it’s one of those things that can gradually mount up.\nIt’s easy to find yourself using versions of libraries that are years old and\nit takes so long to update them all individually.\nThis puts everything in one place and gives a framework for handling it.<\/p>\n","protected":false},"excerpt":{"rendered":"
It’s best if you can avoid re-inventing the wheel. If someone has already written the code you need then it can save a lot of time. Although you should probably make sure about licences before incorporating it. That could be copy-pasting something off a web page but, especially for bigger bits of code, far better […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[10,18],"class_list":["post-448","post","type-post","status-publish","format-standard","hentry","category-general","tag-builds","tag-tools"],"_links":{"self":[{"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/posts\/448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/comments?post=448"}],"version-history":[{"count":1,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/posts\/448\/revisions"}],"predecessor-version":[{"id":449,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/posts\/448\/revisions\/449"}],"wp:attachment":[{"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/media?parent=448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/categories?post=448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/permutationcity.co.uk\/bp\/wp-json\/wp\/v2\/tags?post=448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}