Docs on publishing of header-only C++ libs (include in node c++ modules)

rational

We are increasingly working on small node C++ modules that depend on header-only C++ libs.
Node.js's Nan module has pioneered a best practice for how to include header only C++ libs in node C++ addons by simply adding a package.json and include_dirs.js file to the root of the project. I think we should follow the lead of howNan does this and package all our C++ header only libs in npm as well as mason. I think publishing in two places is worth it because it makes including the libraries from node modules very easy and consistent with how JS modules work.

method

Add:

• package.json
• include_dirs.js
• files parameter to package.json so that only the include/ directory is included

Example:

{
    "name": "@mapbox/geometry-hpp",
    "version": "0.9.0",
    "description": "A C++ header only geometry type library",
    "main": "./include_dirs.js",
    "repository"   :  {
      "type" : "git",
      "url"  : "git://github.com/mapbox/geometry.hpp.git"
    },
    "files": [
         "include"
    ]
}

Then test that only the right files are going to be packaged:

npm pack
tar -ztvf *tgz

^^ that should list just the headers and the default files npm includes like README.md and package.json etc

Examples:

• https://github.com/mapbox/protozero/pull/59
• https://github.com/osmcode/libosmium/pull/186

Example use case:

• https://github.com/springmeyer/node-osmium-count/blob/master/package.json#L17

Individua le librerie C++ header-only in questo repository e confronta il pattern di package.json e include_dirs.js di Nan con gli esempi collegati. Aggiungi i metadati del pacchetto richiesti per ogni libreria, quindi esegui npm pack e ispeziona il tarball per confermare che contenga gli header e solo i file predefiniti di npm.