add base-n (#1918)

packages/b/base-n/xmake.lua

@@ -0,0 +1,27 @@
+package("base-n")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://github.com/azawadzki/base-n")
+    set_description("A small, single-header library which provides standard Base16, Base32, Base64, and custom Base-N encoding support.")
+    set_license("MIT")
+
+    add_urls("https://github.com/azawadzki/base-n.git")
+    add_versions("2020.05.28", "7573e77c0b9b0e8a5fb63d96dbde212c921993b4")
+
+    on_install(function (package)
+        os.cp("include/basen.hpp", package:installdir("include"))
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            #include <string>
+            #include <iostream>
+            #include <basen.hpp>
+            
+            void test () {
+                std::string in = "test";
+                std::string encoded;
+                bn::encode_b64(in.begin(), in.end(), back_inserter(encoded));
+                std::cout << encoded << std::endl; 
+            }
+        ]]}, {configs = {languages = "c++11"}, includes = "basen.hpp"}))
+    end)