[rsm-mmio] Add package (#2150 An error occurred )

* [rsm-mmio] Add package

* [rsm-mmio] Poke CI

* [rsm-mmio] License

* [rsm-mmio] Add git url

* [rsm-mmio] Support `shared`

* [rsm-mmio] Export classes

packages/r/rsm-mmio/xmake.lua

@@ -0,0 +1,35 @@
+package("rsm-mmio")
+    set_homepage("https://github.com/Ryan-rsm-McKenzie/mmio")
+    set_description("A cross-platform memory-mapped io library for C++")
+    set_license("MIT")
+
+    add_urls("https://github.com/Ryan-rsm-McKenzie/mmio/archive/refs/tags/$(version).tar.gz",
+             "https://github.com/Ryan-rsm-McKenzie/mmio.git")
+    add_versions("2.0.0", "360dddf74a97bd0a7eb41378cc59f2a69871dabfd36c55bf027429ac54930d5b")
+
+    on_install(function (package)
+        io.writefile("xmake.lua", [[
+            add_rules("mode.debug", "mode.release")
+            set_languages("c++17")
+            target("rsm-mmio")
+                set_kind("$(kind)")
+                add_files("src/**.cpp")
+                add_includedirs("include/")
+                add_headerfiles("include/(**.hpp)")
+                if is_plat("windows") and is_kind("shared") then
+                    add_rules("utils.symbols.export_all", {export_classes = true})
+                end
+        ]])
+        local configs = {}
+        configs.kind = package:config("shared") and "shared" or "static"
+        import("package.tools.xmake").install(package, configs)
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            void test() {
+                mmio::mapped_file_source f;
+                assert(!f.is_open());
+            }
+        ]]}, {configs = {languages = "c++17"}, includes = {"mmio/mmio.hpp", "assert.h"}}))
+    end)