Added MappingFileSystemAdapter and adjusted some more stuff in the VFS module.

source/mijin/virtual_filesystem/filesystem.hpp

@@ -79,7 +79,6 @@ class FileSystemAdapter
 public:
     virtual ~FileSystemAdapter() = default;
 
-    [[nodiscard]] virtual std::vector<fs::path> getRoots() = 0;
     [[nodiscard]] virtual fs::path getHomeFolder() = 0;
     [[nodiscard]] virtual std::vector<FileInfo> listFiles(const fs::path& folder) = 0;
     [[nodiscard]] virtual FileInfo getFileInfo(const fs::path& file) = 0;
@@ -92,7 +91,6 @@ public:
 class OSFileSystemAdapter : public FileSystemAdapter
 {
 public:
-    std::vector<fs::path> getRoots() override;
     fs::path getHomeFolder() override;
     std::vector<FileInfo> listFiles(const fs::path& folder) override;
     FileInfo getFileInfo(const fs::path& file) override;
@@ -153,6 +151,30 @@ inline std::string formatFileSize(std::size_t sizeInBytes)
     return oss.str();
 }
 
+namespace vfs_pipe
+{
+template<typename TReal, typename TAdapter = FileSystemAdapter>
+struct Builder
+{
+    using adapter_t = TAdapter;
+
+    operator std::unique_ptr<FileSystemAdapter>()
+    {
+        return static_cast<TReal&>(*this).build();
+    }
+};
+
+struct OSBuilder : Builder<OSBuilder, OSFileSystemAdapter>
+{
+    std::unique_ptr<OSFileSystemAdapter> build()
+    {
+        return std::make_unique<OSFileSystemAdapter>();
+    }
+};
+
+[[nodiscard]]
+inline OSBuilder os() noexcept { return {}; }
+}
 } // namespace mijin
 
 template<>