Different temp dir impls per platform

src/dds/temp.hpp

 
         impl(const impl&) = delete;
 
-        ~impl();
+        ~impl() {
+            std::error_code ec;
+            if (fs::exists(path, ec)) {
+                fs::remove_all(path, ec);
+            }
+        }
     };
 
     std::shared_ptr<impl> _ptr;

src/dds/temp.cpp → src/dds/temp.nix.cpp

+#ifndef _WIN32
 #include "./temp.hpp"
 
 using namespace dds;
     auto path = fs::path(tempdir_path);
     return std::make_shared<impl>(std::move(path));
 }
-
-temporary_dir::impl::~impl() {
-    std::error_code ec;
-    if (fs::exists(path, ec)) {
-        fs::remove_all(path, ec);
-    }
-}
+#endif

src/dds/temp.win.cpp

+#ifdef _WIN32
+#include "./temp.hpp"
+
+#include <memory>
+
+#include <rpc.h>
+
+#include <cassert>
+
+using namespace dds;
+
+temporary_dir temporary_dir::create() {
+    auto base = fs::temp_directory_path();
+
+    ::UUID uuid;
+    auto status = ::UuidCreate(&uuid);
+    assert(status == RPC_S_OK || status == RPC_S_UUID_LOCAL_ONLY
+           || status == RPC_S_UUID_NO_ADDRESS);
+
+    RPC_CSTR uuid_str;
+    ::UuidToStringA(&uuid, &uuid_str);
+    std::string uuid_std_str(reinterpret_cast<const char*>(uuid_str));
+    ::RpcStringFree(&uuid_str);
+
+    auto new_dir = base / uuid_std_str;
+    std::error_code ec;
+    fs::create_directory(new_dir);
+    return std::make_shared<impl>(std::move(new_dir));
+}
+#endif