Fixed compilation of boxed_object.hpp in non-debug builds.

SModule

@@ -16,6 +16,7 @@ mijin_sources = Split("""
     source/mijin/platform/folders.cpp
     source/mijin/util/os.cpp
     source/mijin/types/name.cpp
+    source/mijin/types/path.cpp
     source/mijin/virtual_filesystem/filesystem.cpp
     source/mijin/virtual_filesystem/memory.cpp
     source/mijin/virtual_filesystem/stacked.cpp

source/mijin/container/boxed_object.hpp

@@ -68,12 +68,12 @@ public:
     BoxedObject(const BoxedObject&) = delete;
     BoxedObject(BoxedObject&&) = delete;
 
-#if MIJIN_BOXED_OBJECT_DEBUG
     constexpr ~BoxedObject() noexcept
     {
+#if MIJIN_BOXED_OBJECT_DEBUG
         MIJIN_ASSERT(!constructed, "BoxedObject::~BoxedObject(): Object has not been destroyed prior to destructor!");
-    }
 #endif
+    }
 
     BoxedObject& operator=(const BoxedObject&) = delete;
     BoxedObject& operator=(BoxedObject&&) = delete;

source/mijin/container/vector_map.hpp

@@ -251,12 +251,13 @@ public:
         return eraseImpl(idx, count);
     }
 
+    template<std::equality_comparable_with<TKey> T>
     [[nodiscard]]
-    iterator find(const TKey& key) MIJIN_NOEXCEPT
+    iterator find(const T& keyValue) MIJIN_NOEXCEPT
     {
         for (std::size_t idx = 0; idx < keys_.size(); ++idx)
         {
-            if (keys_[idx] == key)
+            if (keys_[idx] == keyValue)
             {
                 return iterator(&keys_[idx], &values_[idx]);
             }
@@ -264,12 +265,13 @@ public:
         return end();
     }
 
+    template<std::equality_comparable_with<TKey> T>
     [[nodiscard]]
-    const_iterator find(const TKey& key) const MIJIN_NOEXCEPT
+    const_iterator find(const T& keyValue) const MIJIN_NOEXCEPT
     {
         for (std::size_t idx = 0; idx < keys_.size(); ++idx)
         {
-            if (keys_[idx] == key)
+            if (keys_[idx] == keyValue)
             {
                 return const_iterator(&keys_[idx], &values_[idx]);
             }
@@ -277,10 +279,11 @@ public:
         return end();
     }
 
+    template<std::equality_comparable_with<TKey> T>
     [[nodiscard]]
-    bool contains(const TKey& key) const MIJIN_NOEXCEPT
+    bool contains(const T& keyValue) const MIJIN_NOEXCEPT
     {
-        return std::ranges::contains(keys_, key);
+        return std::ranges::contains(keys_, keyValue);
     }
 private:
     iterator eraseImpl(std::ptrdiff_t idx, std::ptrdiff_t count = 1) MIJIN_NOEXCEPT

source/mijin/debug/assert.hpp

@@ -19,7 +19,6 @@
 #pragma comment(lib, "kernel32")
 extern "C" __declspec(dllimport) void __stdcall DebugBreak();
 #define MIJIN_TRAP() DebugBreak()
-#define MIJIN_FUNC() __FUNCSIG__
 #else // _WIN32
 #include <unistd.h>
 #define MIJIN_TRAP()                            \
@@ -34,7 +33,6 @@ extern "C" __declspec(dllimport) void __stdcall DebugBreak();
         : "rcx", "r11", "memory"                \
     );                                          \
 }
-#define MIJIN_FUNC() "" // TODO: __PRETTY_FUNCTION__ is not working for some reason -.-
 #endif // !_WIN32
 
 namespace mijin

source/mijin/logging/logger.hpp

@@ -12,6 +12,7 @@
 #include <vector>
 #include "../internal/common.hpp"
 #include "../util/annot.hpp"
+#include "../util/iterators.hpp"
 
 namespace mijin
 {
@@ -148,11 +149,8 @@ public:
     {}
 
     BaseLogger(const BaseLogger&) = default;
-
     BaseLogger(BaseLogger&&) = default;
-
     BaseLogger& operator=(const BaseLogger&) = default;
-
     BaseLogger& operator=(BaseLogger&&) = default;
 
     void addSink(sink_t& sink)
@@ -191,12 +189,28 @@ public:
 
     template<typename... TArgs>
     void log(const level_t& level, const channel_t& channel, std::source_location sourceLocation,
-             std::basic_format_string<char_t, std::type_identity_t<TArgs>...> fmt, TArgs&& ... args) const
-             MIJIN_NOEXCEPT_IF(noexcept(std::declval<allocator_t>().allocate(1)))
+             std::basic_format_string<char_t, std::type_identity_t<TArgs>...> fmt, TArgs&& ... args) const MIJIN_NOEXCEPT
     {
-        string_t buffer(allocator_t(mSinks.get_allocator()));
-        std::format_to(std::back_inserter(buffer), fmt, std::forward<TArgs>(args)...);
-        log(level, channel, std::move(sourceLocation), buffer.c_str());
+        // TODO: make the logger use a traits struct to make this adjustable
+        static constexpr std::size_t BUFFER_SIZE = 256;
+        std::array<char_t, BUFFER_SIZE> buffer;
+
+        // first try to write into a buffer on the stack
+        FixedArrayOutputIterator itAfter = std::format_to(FixedArrayOutputIterator(buffer), fmt, std::forward<TArgs>(args)...);
+        *itAfter = '\0';
+        ++itAfter;
+        if (!itAfter.didOverflow())
+        {
+            log(level, channel, std::move(sourceLocation), buffer.data());
+            return;
+        }
+
+        // if that didn't work, allocate more space
+        const std::size_t newBufferSize = itAfter.getCounter();
+        char_t* newBuffer = static_cast<char_t*>(alloca(newBufferSize * sizeof(char_t)));
+        const std::format_to_n_result result = std::format_to_n(newBuffer, newBufferSize - 1, fmt, std::forward<TArgs>(args)...);
+        *result.out = '\0';
+        log(level, channel, std::move(sourceLocation), newBuffer);
     }
 };
 

source/mijin/memory/object_pool.hpp

@@ -7,56 +7,317 @@
 #include <array>
 #include <cstddef>
 #include <cstdint>
-#include <limits>
-#include <memory>
-#include <vector>
+#include "../internal/common.hpp"
 #include "../debug/assert.hpp"
+#include "../util/align.hpp"
 
 namespace mijin
 {
-template<typename TObject, std::size_t OBJECTS_PER_PAGE = 1024>
-class ObjectPool
+namespace impl
 {
-private:
-    struct GapInfo
+struct ObjectPoolGap
 {
-        std::uint32_t objectCount;
-        std::uint32_t nextGap;
-    };
-    static constexpr std::size_t ALIGN = std::max(alignof(TObject), alignof(GapInfo));
+    std::uint16_t nextGapOffset;
+    std::uint16_t remainingObjects;
 
-    struct alignas(ALIGN) ObjectData
-    {
-        std::array<std::byte, sizeof(TObject)> bytes;
-    };
-    struct Page
-    {
-        std::uint32_t freeOffset = 0;
-        std::array<ObjectData, OBJECTS_PER_PAGE> data;
-    };
-
-    std::vector<std::unique_ptr<Page>> pages;
-public:
-    [[nodiscard]] TObject* allocate(std::size_t count = 1) noexcept;
-    void free(TObject* object, std::size_t count = 1) noexcept;
+    ObjectPoolGap* nextGap() noexcept {
+        return nextGapOffset == 0 ? nullptr : reinterpret_cast<ObjectPoolGap*>(reinterpret_cast<std::byte*>(this) + nextGapOffset);
+    }
 };
 
 template<typename TObject, std::size_t OBJECTS_PER_PAGE>
-TObject* ObjectPool<TObject, OBJECTS_PER_PAGE>::allocate(std::size_t count) noexcept
+struct ObjectPoolPage
 {
-    MIJIN_ASSERT(count <= OBJECTS_PER_PAGE, "Cannot allocate more than OBJECTS_PER_PAGE elements at once!");
+    ObjectPoolGap* firstGap;
+    ObjectPoolPage* nextPage = nullptr;
+    std::array<std::byte, OBJECTS_PER_PAGE * MIJIN_STRIDEOF(TObject)> data;
+
+    ObjectPoolPage() noexcept
+    {
+        firstGap = reinterpret_cast<ObjectPoolGap*>(data.data());
+        firstGap->nextGapOffset = 0;
+        firstGap->remainingObjects = OBJECTS_PER_PAGE;
+    }
+};
+}
+
+template<typename TObject, std::size_t OBJECTS_PER_PAGE>
+class ObjectPoolIterator
+{
+public:
+    using value_type = TObject;
+    using difference_type = std::ptrdiff_t;
+private:
+    using gap_t = impl::ObjectPoolGap;
+    using page_t = impl::ObjectPoolPage<TObject, OBJECTS_PER_PAGE>;
+
+    page_t* currentPage_ = nullptr;
+    gap_t* currentGap_ = nullptr;
+    std::uint16_t currentObject_ = 0;
+
+    explicit ObjectPoolIterator(page_t& firstPage) noexcept
+    {
+        seekNextOnPage(firstPage);
+    }
+public:
+    ObjectPoolIterator() noexcept = default;
+    ObjectPoolIterator(const ObjectPoolIterator&) noexcept = default;
+
+    ObjectPoolIterator& operator=(const ObjectPoolIterator&) noexcept = default;
+
+    auto operator<=>(const ObjectPoolIterator&) const noexcept = default;
+
+    TObject& operator*() const noexcept { return getObject(); }
+    TObject* operator->() const noexcept { return &getObject(); }
+
+    ObjectPoolIterator& operator++() noexcept
+    {
+        seekNext();
+        return *this;
+    }
+
+    ObjectPoolIterator operator++(int) const noexcept
+    {
+        ObjectPoolIterator copy(*this);
+        ++(*this);
+        return copy;
+    }
+private:
+    TObject& getObject() const noexcept
+    {
+        MIJIN_ASSERT(currentGap_ != nullptr, "Attempting to dereference an invalid iterator.");
+        return *(reinterpret_cast<TObject*>(currentGap_) + currentGap_->remainingObjects + currentObject_);
+    }
+
+    bool seekNextOnPage(page_t& firstPage) noexcept
+    {
+        for (page_t* page = &firstPage; page != nullptr; page = page->nextPage)
+        {
+            if (page->firstGap != nullptr && seekNextInGap(*page->firstGap))
+            {
+                currentPage_ = page;
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool seekNextInGap(gap_t& firstGap) noexcept
+    {
+        for (gap_t* gap = &firstGap; gap != nullptr; gap = gap->nextGap())
+        {
+            if (gap->remainingObjects < OBJECTS_PER_PAGE)
+            {
+                currentGap_ = gap;
+                currentObject_ = 0;
+                return true;
+            }
+        }
+        return false;
+    }
+
+    void seekNext() noexcept
+    {
+        if (++currentObject_ < OBJECTS_PER_PAGE - currentGap_->remainingObjects)
+        {
+            return;
+        }
+        if (currentGap_->nextGapOffset != 0 && seekNextInGap(*currentGap_->nextGap())) {
+            return;
+        }
+        if (currentPage_->nextPage != nullptr && seekNextOnPage(*currentPage_->nextPage)) {
+            return;
+        }
+        currentPage_ = nullptr;
+        currentGap_ = nullptr;
+        currentObject_ = 0;
+    }
+
+    template<typename TObject2, std::size_t OBJECTS_PER_PAGE2, template<typename> typename TAllocator>
+    friend class ObjectPool;
+};
+
+template<typename TObject, std::size_t OBJECTS_PER_PAGE = 1024, template<typename> typename TAllocator = MIJIN_DEFAULT_ALLOCATOR>
+class ObjectPool
+{
+public:
+    using iterator = ObjectPoolIterator<TObject, OBJECTS_PER_PAGE>;
+    using const_iterator = iterator;
+private:
+    using gap_t = impl::ObjectPoolGap;
+    using page_t = impl::ObjectPoolPage<TObject, OBJECTS_PER_PAGE>;
+    
+    static_assert(sizeof(gap_t) <= sizeof(TObject));
+
+    [[no_unique_address]] TAllocator<page_t> allocator_;
+    page_t* firstPage = nullptr;
+public:
+    explicit ObjectPool(TAllocator<void> allocator = {}) MIJIN_NOEXCEPT_IF((std::is_nothrow_constructible_v<TAllocator<page_t>, TAllocator<void>&&>))
+        : allocator_(std::move(allocator))
+    {
+    }
+    ObjectPool(const ObjectPool&) = delete;
+    ObjectPool(ObjectPool&&) = default;
+
+    ObjectPool& operator=(const ObjectPool&) = delete;
+    ObjectPool& operator=(ObjectPool&&) = default;
+
+    [[nodiscard]]
+    TObject* allocate(std::size_t count = 1) noexcept
+    {
+        MIJIN_ASSERT(count <= OBJECTS_PER_PAGE, "Cannot allocate that many objects at once.");
+
         // first try to find a free spot in the existing pages
-
-    for (std::unique_ptr<Page>& page : pages)
+        for (page_t* page = firstPage; page != nullptr; page = page->nextPage)
         {
-        std::uint32_t offset = page->freeOffset;
-        while (offset < OBJECTS_PER_PAGE)
-        {
-            GapInfo& gapInfo = *std::bit_cast<GapInfo*>(&page->data[offset]);
+            if (TObject* result = allocateFromPage(*page, count); result != nullptr) {
+                return result;
+            }
+        }
 
+        // nothing found in the existing pages, allocate a new one and return memory from there
+        page_t* newPage = ::new (allocator_.allocate(1)) page_t;
+
+        if (firstPage == nullptr)
+        {
+            firstPage = newPage;
+        }
+        else
+        {
+            page_t* lastPage = firstPage;
+            for (; lastPage->nextPage != nullptr; lastPage = lastPage->nextPage);
+            lastPage->nextPage = newPage;
+        }
+        return allocateFromPage(*newPage, count);
+    }
+
+    void deallocate(TObject* object, std::size_t count = 1) noexcept
+    {
+        std::byte* const objectPtr = reinterpret_cast<std::byte*>(object); // for easier comparison
+        for (page_t* page = firstPage; page != nullptr; page = page->nextPage)
+        {
+            // first find the page it's in
+            std::byte* pageStart = page->data.data();
+            std::byte* pageEnd = pageStart + (OBJECTS_PER_PAGE * sizeof(TObject));
+
+            if (objectPtr >= pageStart && objectPtr <= pageEnd)
+            {
+                // then the corresponding gap
+                if (page->firstGap == nullptr)
+                {
+                    // everything is used, create a new gap
+                    gap_t* newGap = reinterpret_cast<gap_t*>(objectPtr);
+                    newGap->remainingObjects = count;
+                    newGap->nextGapOffset = 0;
+                    page->firstGap = newGap;
+                    return;
+                }
+
+                for (gap_t* gap = page->firstGap; gap != nullptr; gap = gap->nextGap())
+                {
+                    std::byte* gapStart = reinterpret_cast<std::byte*>(gap);
+                    std::byte* gapEnd = gap->nextGapOffset == 0 ? pageEnd : gapStart + gap->nextGapOffset;
+                    if (objectPtr > gapStart && objectPtr < gapEnd)
+                    {
+                        if (objectPtr + (count * sizeof(TObject)) == gapEnd)
+                        {
+                            // deallocating right from the end -> just increase the gap remainingObjects
+                            gap->remainingObjects += count;
+                            mergeGaps(gap);
+                        }
+                        else
+                        {
+                            // deallocating from the middle -> create a new gap
+                            gap_t* newGap = reinterpret_cast<gap_t*>(objectPtr);
+                            newGap->remainingObjects = count;
+                            newGap->nextGapOffset = gap->nextGapOffset == 0 ? 0 : (gapEnd - reinterpret_cast<std::byte*>(newGap));
+                            gap->nextGapOffset -= objectPtr - gapStart;
+                            mergeGaps(newGap);
+                        }
+                        return;
                     }
                 }
             }
+        }
+    }
+
+    template<typename... TArgs>
+    [[nodiscard]]
+    TObject* create(TArgs&&... args) noexcept
+    {
+        TObject* result = allocate();
+        if (result == nullptr) {
+            return nullptr;
+        }
+        return ::new (result) TObject(std::forward<TArgs>(args)...);
+    }
+
+    [[nodiscard]]
+    TObject* createMultiple(std::size_t count = 1) noexcept
+    {
+        TObject* result = allocate(count);
+        if (result == nullptr) {
+            return nullptr;
+        }
+        return ::new (result) TObject[count];
+    }
+
+    void destroy(TObject* ptr, std::size_t count = 1) noexcept
+    {
+        for (std::size_t idx = 0; idx < count; ++idx) {
+            ptr[idx].~TObject();
+        }
+        deallocate(ptr, count);
+    }
+
+    [[nodiscard]]
+    iterator begin() const noexcept { return firstPage != nullptr ? iterator(*firstPage) : iterator(); }
+
+    [[nodiscard]]
+    iterator end() const noexcept { return {}; }
+private:
+    TObject* allocateFromPage(page_t& page, std::size_t count)
+    {
+        gap_t* previousGap = nullptr;
+        for (gap_t* gap = page.firstGap; gap != nullptr; previousGap = gap, gap = gap->nextGap())
+        {
+            if (gap->remainingObjects == count)
+            {
+                // exactly the correct size
+                if (previousGap != nullptr) {
+                    previousGap->nextGapOffset += gap->nextGapOffset;
+                }
+                else {
+                    page.firstGap = gap->nextGap();
+                }
+                return reinterpret_cast<TObject*>(gap);
+            }
+            else if (gap->remainingObjects > count)
+            {
+                // still enough space
+                TObject* memory = reinterpret_cast<TObject*>(gap) + gap->remainingObjects - count;
+                gap->remainingObjects -= count;
+                return reinterpret_cast<TObject*>(memory);
+            }
+        }
+        return nullptr;
+    }
+
+    void mergeGaps(gap_t* start) noexcept
+    {
+        while (start->nextGapOffset != 0 && start->remainingObjects == start->nextGapOffset * sizeof(TObject))
+        {
+            gap_t& next = *start->nextGap();
+            start->remainingObjects += start->nextGap()->remainingObjects;
+            if (next.nextGapOffset == 0) {
+                start->nextGapOffset = 0;
+            }
+            else {
+                start->nextGapOffset += next.nextGapOffset;
+            }
+        }
+    }
+};
 } // namespace mijin
 
 #endif // !defined(MIJIN_MEMORY_OBJECT_POOL_HPP_INCLUDED)

source/mijin/types/path.cpp

@@ -0,0 +1,40 @@
+
+#include "./path.hpp"
+
+#include <filesystem>
+
+namespace fs = std::filesystem;
+
+namespace mijin
+{
+
+//
+// internal defines
+//
+
+//
+// internal constants
+//
+
+//
+// internal types
+//
+
+//
+// internal variables
+//
+
+//
+// internal functions
+//
+
+
+//
+// public functions
+//
+
+NativePath getWorkingDirectory()
+{
+    return fs::current_path().generic_string();
+}
+} // namespace mijin

source/mijin/types/path.hpp

@@ -0,0 +1,511 @@
+
+#pragma once
+
+#if !defined(MIJIN_TYPES_PATH_HPP_INCLUDED)
+#define MIJIN_TYPES_PATH_HPP_INCLUDED 1
+
+#include "../debug/assert.hpp"
+#include "../internal/common.hpp"
+#include "../util/traits.hpp"
+
+#include <ranges>
+#include <string>
+#include <type_traits>
+
+namespace mijin
+{
+
+template<typename T>
+concept BasePathType = requires(const T& path)
+{
+    typename T::traits_t;
+    typename T::char_t;
+    typename T::char_traits_t;
+    typename T::allocator_t;
+    typename T::string_t;
+    typename T::string_view_t;
+    typename T::size_type;
+    typename T::difference_type;
+    typename T::path_view_t;
+    { T::SEPARATOR } -> std::convertible_to<typename T::char_t>;
+    { path.stringView() } -> std::convertible_to<typename T::string_view_t>;
+};
+
+template<typename T>
+concept PathType = BasePathType<T> && std::is_same_v<typename T::char_t, char>;
+
+template<typename T>
+concept WPathType = BasePathType<T> && std::is_same_v<typename T::char_t, wchar_t>;
+
+template<typename TChar, TChar separator = TChar('/')>
+struct DefaultPathTraits
+{
+    using char_t = TChar;
+    using char_traits_t = std::char_traits<TChar>;
+    using allocator_t = std::allocator<TChar>;
+    using string_t = std::basic_string<char_t, char_traits_t, allocator_t>;
+    using string_view_t = std::basic_string_view<char_t, char_traits_t>;
+    using size_type = string_view_t::size_type;
+    using difference_type = string_view_t::difference_type;
+    static constexpr char_t SEPARATOR = separator;
+
+    static constexpr bool isAbsolute(string_view_t path) MIJIN_NOEXCEPT
+    {
+        return !path.empty() && path[0] == SEPARATOR;
+    }
+};
+
+template<typename TChar = char, typename TTraits = DefaultPathTraits<TChar>>
+class BasePathView;
+
+template<typename TConcrete, typename TChar = char, typename TTraits = DefaultPathTraits<TChar>>
+class MixinPath;
+
+namespace impl
+{
+template<typename TChar, typename TTraits, TChar separator>
+class BasePathIterator
+{
+private:
+    std::string_view full_;
+    std::string_view::iterator pos_;
+    std::string_view::iterator next_;
+
+    BasePathIterator(std::string_view full, std::string_view::iterator pos) MIJIN_NOEXCEPT : full_(full), pos_(pos) {
+        if (pos != full_.end() && *pos == separator) {
+            ++pos;
+        }
+        findNext();
+    }
+public:
+    BasePathIterator() MIJIN_NOEXCEPT : pos_(full_.end()), next_(full_.end()) {}
+    BasePathIterator(const BasePathIterator&) noexcept = default;
+
+    BasePathIterator& operator=(const BasePathIterator&) noexcept = default;
+
+    bool operator==(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ == other.pos_; }
+    bool operator!=(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ != other.pos_; }
+    bool operator<(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ < other.pos_; }
+    bool operator<=(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ <= other.pos_; }
+    bool operator>(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ > other.pos_; }
+    bool operator>=(const BasePathIterator& other) MIJIN_NOEXCEPT { MIJIN_ASSERT(full_ == other.full_, "Comparing unrelated iterators."); return pos_ >= other.pos_; }
+
+    std::string_view operator*() const MIJIN_NOEXCEPT
+    {
+        MIJIN_ASSERT(pos_ != full_.end(), "Dereferencing an invalid iterator.");
+        return {pos_, next_};
+    }
+
+    BasePathIterator& operator++() MIJIN_NOEXCEPT
+    {
+        MIJIN_ASSERT(pos_ != full_.end(), "Iterating past end.");
+        if (next_ == full_.end()) {
+            pos_ = full_.end();
+        }
+        else
+        {
+            pos_ = std::next(next_);
+            findNext();
+        }
+        return *this;
+    }
+
+    BasePathIterator operator++(int) const MIJIN_NOEXCEPT
+    {
+        BasePathIterator copy(*this);
+        ++copy;
+        return copy;
+    }
+
+    // TODO
+    // BasePathIterator& operator--() MIJIN_NOEXCEPT
+    // {
+    //     MIJIN_ASSERT(pos_ != full_.begin(), "Iterating past begin.");
+    //     next_ = std::prev(pos_);
+    //     pos_ = std::find(std::reverse_iterator(next_), std::reverse_iterator(full_.begin()), separator).base();
+    // }
+private:
+    void findNext()
+    {
+        next_ = std::find(pos_, full_.end(), separator);
+    }
+
+    template<typename TConcrete, typename TCharOther, typename TTraitsOther>
+    friend class ::mijin::MixinPath;
+};
+}
+
+template<typename TConcrete, typename TChar, typename TTraits>
+class MixinPath
+{
+public:
+    using traits_t = TTraits;
+    using char_t = typename traits_t::char_t;
+    using char_traits_t = typename traits_t::char_traits_t;
+    using allocator_t = typename traits_t::allocator_t;
+    using string_t = typename traits_t::string_t;
+    using string_view_t = typename traits_t::string_view_t;
+    using size_type = typename traits_t::size_type;
+    using difference_type = typename traits_t::difference_type;
+    using path_view_t = BasePathView<TChar, traits_t>;
+    using iterator = impl::BasePathIterator<char_t, char_traits_t, traits_t::SEPARATOR>;
+    using const_iterator = iterator;
+    static constexpr char_t SEPARATOR = traits_t::SEPARATOR;
+
+    constexpr bool operator==(string_view_t stringView) const MIJIN_NOEXCEPT { return stringView() == stringView; }
+    constexpr bool operator==(const TChar* cString) const MIJIN_NOEXCEPT { return stringView() == cString; }
+
+    [[nodiscard]]
+    constexpr string_view_t getName() const MIJIN_NOEXCEPT;
+
+    [[nodiscard]]
+    constexpr path_view_t getParent() const MIJIN_NOEXCEPT;
+
+    [[nodiscard]]
+    constexpr string_view_t stringView() const MIJIN_NOEXCEPT
+    {
+        return static_cast<const TConcrete*>(this)->stringViewImpl();
+    }
+
+    [[nodiscard]]
+    constexpr bool empty() const MIJIN_NOEXCEPT { return stringView().empty(); }
+
+    [[nodiscard]]
+    constexpr size_type size() const MIJIN_NOEXCEPT { return stringView().size(); }
+
+    [[nodiscard]]
+    constexpr bool isAbsolute() const MIJIN_NOEXCEPT
+    {
+        return traits_t::isAbsolute(stringView());
+    }
+
+    [[nodiscard]]
+    iterator begin() const MIJIN_NOEXCEPT { return iterator(stringView(), stringView().begin()); }
+
+    [[nodiscard]]
+    iterator end() const MIJIN_NOEXCEPT { return iterator(stringView(), stringView().end()); }
+private:
+
+    template<typename TConcreteOther, typename TCharOther, typename TTraitsOther>
+    friend class MixinPath;
+};
+
+template<typename TConcreteA, typename TConcreteB, typename TChar, typename TTraits>
+constexpr bool operator==(const MixinPath<TConcreteA, TChar, TTraits>& pathA, const MixinPath<TConcreteB, TChar, TTraits>& pathB)  MIJIN_NOEXCEPT
+{
+    return pathA.stringView() == pathB.stringView();
+}
+
+template<typename TChar = char, typename TTraits = DefaultPathTraits<TChar>>
+class BasePath : public MixinPath<BasePath<TChar, TTraits>, TChar, TTraits>
+{
+public:
+    using mixin_t = MixinPath<BasePath<TChar, TTraits>, TChar, TTraits>;
+    using typename mixin_t::traits_t;
+    using typename mixin_t::char_t;
+    using typename mixin_t::char_traits_t;
+    using typename mixin_t::allocator_t;
+    using typename mixin_t::string_t;
+    using typename mixin_t::string_view_t;
+    using typename mixin_t::difference_type;
+    using typename mixin_t::path_view_t;
+    static constexpr char_t SEPARATOR = mixin_t::SEPARATOR;
+private:
+    struct NoSimplify {};
+
+    string_t storage_;
+
+    constexpr BasePath(string_t storage, NoSimplify) MIJIN_NOEXCEPT_IF(std::is_nothrow_move_constructible<string_t>()) : storage_(std::move(storage)) {}
+public:
+    constexpr BasePath() = default;
+    constexpr BasePath(const BasePath&) = default;
+    constexpr BasePath(BasePath&&) = default;
+    constexpr BasePath(string_t string) MIJIN_NOEXCEPT_IF(std::is_nothrow_move_constructible<string_t>()) : storage_(std::move(string)) {
+        simplify();
+    }
+    constexpr BasePath(const char_t* cString, allocator_t allocator = {}) : BasePath(string_t(cString, std::move(allocator))) {}
+    constexpr BasePath(string_view_t stringView, allocator_t allocator = {}) : BasePath(string_t(stringView, std::move(allocator))) {}
+    template<typename TConcreteOther> requires (!std::is_same_v<BasePath<TChar, TTraits>, TConcreteOther>)
+    explicit constexpr BasePath(const MixinPath<TConcreteOther, TChar, TTraits> other, allocator_t allocator = {}) : BasePath(string_t(other.stringView(), std::move(allocator)), NoSimplify()) {}
+
+    constexpr BasePath& operator=(const BasePath&) = default;
+    constexpr BasePath& operator=(BasePath&&) = default;
+
+    constexpr auto operator<=>(const BasePath&) const noexcept = default;
+    using mixin_t::operator==;
+
+    template<typename TConcreteOther>
+    BasePath& operator/=(const MixinPath<TConcreteOther, char_t, traits_t>& other);
+    BasePath& operator/=(string_view_t more);
+
+    template<typename TConcreteOther>
+    BasePath operator/(const MixinPath<TConcreteOther, char_t, traits_t>& other) const;
+    BasePath operator/(string_view_t more) const;
+
+    [[nodiscard]]
+    constexpr const string_t& string() const MIJIN_NOEXCEPT
+    {
+        return storage_;
+    }
+
+    [[nodiscard]]
+    constexpr string_view_t stringViewImpl() const MIJIN_NOEXCEPT
+    {
+        return storage_;
+    }
+private:
+    constexpr void simplify() MIJIN_NOEXCEPT;
+};
+
+using Path = BasePath<char>;
+using WPath = BasePath<wchar_t>;
+
+using NativePath = Path; // TODO
+
+template<typename TChar, typename TTraits>
+class BasePathView : public MixinPath<BasePathView<TChar, TTraits>, TChar, TTraits>
+{
+public:
+    using mixin_t = MixinPath<BasePathView<TChar, TTraits>, TChar, TTraits>;
+    using typename mixin_t::char_t;
+    using typename mixin_t::string_view_t;
+private:
+    string_view_t view_;
+public:
+    constexpr BasePathView() noexcept = default;
+    constexpr BasePathView(const BasePathView&) noexcept = default;
+    explicit constexpr BasePathView(string_view_t view) MIJIN_NOEXCEPT : view_(view) {}
+    template<typename TIterator>
+    constexpr BasePathView(const TIterator& begin, const TIterator& end) MIJIN_NOEXCEPT : view_(begin, end) {}
+    template<typename TConcreteOther> requires (!std::is_same_v<BasePathView<TChar, TTraits>, TConcreteOther>)
+    constexpr BasePathView(const MixinPath<TConcreteOther>& other) MIJIN_NOEXCEPT : view_(other.stringView()) {}
+
+    constexpr BasePathView& operator=(const BasePathView&) noexcept = default;
+
+    constexpr auto operator<=>(const BasePathView&) const noexcept = default;
+    using mixin_t::operator==;
+
+    [[nodiscard]]
+    constexpr string_view_t stringViewImpl() const MIJIN_NOEXCEPT
+    {
+        return view_;
+    }
+};
+
+using PathView = BasePathView<char>;
+using WPathView = BasePathView<wchar_t>;
+
+using NativePathView = PathView; // TODO
+
+template<typename TConcrete, typename TChar, typename TTraits>
+constexpr auto MixinPath<TConcrete, TChar, TTraits>::getName() const MIJIN_NOEXCEPT -> string_view_t
+{
+    const string_view_t strView = stringView();
+    auto it = std::ranges::find(std::ranges::reverse_view(strView), SEPARATOR).base();
+    return {it, strView.end()};
+}
+
+template<typename TConcrete, typename TChar, typename TTraits>
+constexpr auto MixinPath<TConcrete, TChar, TTraits>::getParent() const MIJIN_NOEXCEPT -> path_view_t
+{
+    const string_view_t strView = stringView();
+    auto it = std::ranges::find(std::ranges::reverse_view(strView), SEPARATOR).base();
+    if (it == strView.begin()) {
+        return {};
+    }
+    if (std::prev(it) == strView.begin()) {
+        return {strView.begin(), it}; // edge case, return "/" instead of nothing
+    }
+    return {strView.begin(), std::prev(it)};
+}
+
+template<typename TChar, typename TTraits>
+template<typename TConcreteOther>
+auto BasePath<TChar, TTraits>::operator/=(const MixinPath<TConcreteOther, char_t, traits_t>& other) -> BasePath&
+{
+    if (other.isAbsolute())
+    {
+        storage_ = other.stringView();
+    }
+    else if (!other.empty())
+    {
+        if (other.stringView()[0] != SEPARATOR)
+        {
+            storage_.reserve(storage_.size() + other.size() + 1);
+            storage_.push_back(SEPARATOR);
+        }
+        storage_.append_range(other.stringView());
+    }
+    return *this;
+}
+
+template<typename TChar, typename TTraits>
+auto BasePath<TChar, TTraits>::operator/=(string_view_t more) -> BasePath&
+{
+    operator/=(path_view_t(more));
+    simplify();
+    return *this;
+}
+
+template<typename TChar, typename TTraits>
+template<typename TConcreteOther>
+auto BasePath<TChar, TTraits>::operator/(const MixinPath<TConcreteOther, char_t, traits_t>& other) const -> BasePath
+{
+    if (other.isAbsolute() || other.empty())
+    {
+        return BasePath(string_t(other.stringView(), storage_.get_allocator()), NoSimplify());
+    }
+    const bool addSeparator = other.stringView()[0] != SEPARATOR;
+    string_t combined(storage_.get_allocator());
+    combined.reserve(storage_.size() + other.stringView().size() + (addSeparator ? 1 : 0));
+    combined.append_range(storage_);
+    if (addSeparator) {
+        combined.push_back(SEPARATOR);
+    }
+    combined.append_range(other.stringView());
+    return BasePath(std::move(combined), NoSimplify());
+}
+
+template<typename TChar, typename TTraits>
+auto BasePath<TChar, TTraits>::operator/(string_view_t other) const -> BasePath
+{
+    BasePath combined = (*this / path_view_t(other));
+    combined.simplify();
+    return combined;
+}
+
+template<typename TChar, typename TTraits>
+constexpr void BasePath<TChar, TTraits>::simplify() MIJIN_NOEXCEPT
+{
+    // step 1: remove double slashes
+    difference_type moveBy = 0;
+    for (auto it = std::next(storage_.begin()); it < storage_.end(); ++it)
+    {
+        const bool doubleSlash = (*it == SEPARATOR && *std::prev(it) == SEPARATOR); // check this before moving the current character, as that might create a double slash itself
+        if (moveBy > 0) {
+            *std::prev(it, moveBy) = *it;
+        }
+        if (doubleSlash) {
+            ++moveBy;
+        }
+    }
+    // step 1.5: remove trailing slash (but only if it's not the only remaining char)
+    if (moveBy < static_cast<difference_type>(storage_.size() - 1) && storage_[storage_.size() - moveBy - 1] == SEPARATOR) {
+        ++moveBy;
+    }
+    storage_.resize(storage_.size() - moveBy);
+
+    // step 2: get rid of any "/.." together with the preceeding segment
+    moveBy = 0;
+    for (auto it = std::next(storage_.begin(), 2); it < storage_.end(); ++it)
+    {
+        if (moveBy > 0)
+        {
+            *std::prev(it, moveBy) = *it;
+        }
+        if (*std::prev(it, moveBy) == TChar('.') && *std::prev(it, moveBy + 1) == TChar('.') && *std::prev(it, moveBy + 2) == SEPARATOR
+            && (std::next(it) == storage_.end() || *std::next(it) == SEPARATOR))
+        {
+            if (std::prev(it, moveBy + 2) == storage_.begin())
+            {
+                // leading "/.." -> just remove it
+                moveBy += 3;
+                continue;
+            }
+            // find the start of the preceeding segment
+            for (auto itStart = std::prev(it, moveBy + 3);; --itStart)
+            {
+                if (*std::prev(itStart) == SEPARATOR || std::prev(itStart) == storage_.begin())
+                {
+                    //     /path/with/../double/dot
+                    // itStart --A     A
+                    // it -------------|
+                    // remove everything from itStart to it + two slashes
+                    moveBy += std::distance(itStart, std::prev(it, moveBy)) + 2; // skip it all
+                    break;
+                }
+            }
+        }
+    }
+    storage_.resize(storage_.size() - moveBy);
+
+    // step 3: eliminate any segments that are just "."
+    moveBy = 0;
+    if (storage_.size() == 1) {
+        return; // just stop it here
+    }
+    for (auto it = storage_.begin(); it < storage_.end(); ++it)
+    {
+        const bool atStart = (it == storage_.begin());
+        const bool atEnd = (std::next(it) == storage_.end());
+        const bool emptyEle = (*it == TChar('.') // char is a dot
+            && (atStart || *std::prev(it, moveBy + 1) == SEPARATOR) // previous is a slash or doesn't exist
+            && (atEnd || *std::next(it) == SEPARATOR)); // next is a slash or doesn't exist
+        if (moveBy > 0) {
+            *std::prev(it, moveBy) = *it;
+        }
+        if (emptyEle) {
+            moveBy += 2;
+            if (!atEnd) {
+                ++it; // skip the next one
+            }
+        }
+    }
+    storage_.resize(storage_.size() - moveBy);
+}
+
+template<typename TChar, TChar separator = TChar('/'), typename TTraits = std::char_traits<TChar>>
+constexpr bool verifyPathString(std::basic_string_view<TChar, TTraits> stringView) MIJIN_NOEXCEPT
+{
+    for (auto it = std::next(stringView.begin()); it < stringView.end(); ++it)
+    {
+        if(*it == separator && *std::prev(it) == separator) {
+            return false; // double slash
+        }
+        if (it != std::next(stringView.begin())
+            && *it == TChar('.') && *std::prev(it) == TChar('.') && *std::prev(it,  2) == separator
+            && (std::next(it) == stringView.end() || *std::next(it) == separator)) {
+            return false; // "/.."
+        }
+        const bool atStart = (it == stringView.begin());
+        const bool atEnd = (std::next(it) == stringView.end());
+        if(*it == TChar('.') // char is a dot
+            && (atStart || *std::prev(it) == separator) // previous is a slash or doesn't exist
+            && (atEnd || *std::next(it) == separator)) // next is a slash or doesn't exist
+        {
+            return false; // "/."
+        }
+    }
+    return true;
+}
+
+consteval PathView operator""_pv(const char* cString, std::size_t len)
+{
+    if (!verifyPathString(std::string_view(cString, len))) {
+        throw "Invalid path string.";
+    }
+    return PathView(std::string_view(cString, len));
+}
+
+consteval WPathView operator""_pv(const wchar_t* cString, std::size_t len)
+{
+    if (!verifyPathString(std::wstring_view(cString, len))) {
+        throw "Invalid path string.";
+    }
+    return WPathView(std::wstring_view(cString, len));
+}
+
+[[nodiscard]]
+NativePath getWorkingDirectory();
+} // namespace mijin
+
+template<mijin::BasePathType TPath>
+struct std::hash<TPath>
+{
+    std::size_t operator()(const TPath& path) const MIJIN_NOEXCEPT
+    {
+        return std::hash<std::string_view>()(path.stringView());
+    }
+};
+
+#endif // !defined(MIJIN_TYPES_PATH_HPP_INCLUDED)

source/mijin/util/annot.hpp

@@ -35,6 +35,10 @@ concept nullable_type = !std::is_same_v<T, std::nullptr_t> && requires(T t) { t
 template<nullable_type T>
 class NotNullable
 {
+public:
+    using wrapped_t = T;
+    using element_type = std::remove_reference_t<decltype(*std::declval<const wrapped_t>())>;
+    using pointer = element_type*;
 private:
     T base_;
 public:
@@ -55,6 +59,12 @@ public:
     {
         MIJIN_ASSERT(base_ != nullptr, "Constructed non-nullable type with nullptr.");
     }
+    template<typename TOther> requires(std::is_base_of_v<typename NotNullable<TOther>::element_type, element_type> && std::is_constructible_v<T, pointer>)
+    explicit constexpr NotNullable(const NotNullable<TOther>& other) MIJIN_NOEXCEPT_IF((std::is_nothrow_constructible_v<T, pointer>))
+            : base_(static_cast<pointer>(&*other))
+    {
+        MIJIN_ASSERT(base_ != nullptr, "Constructed non-nullable type with nullptr.");
+    }
     template<typename TOther> requires(std::is_constructible_v<T, TOther&&>)
     constexpr NotNullable(NotNullable<TOther>&& other) MIJIN_NOEXCEPT_IF((std::is_nothrow_constructible_v<T, TOther&&>))
             : base_(std::exchange(other.base_, nullptr))

source/mijin/util/common_macros.hpp

@@ -4,8 +4,18 @@
 #if !defined(MIJIN_UTIL_COMMON_MACROS_HPP_INCLUDED)
 #define MIJIN_UTIL_COMMON_MACROS_HPP_INCLUDED 1
 
+#include "../detect.hpp"
+
 #define MIJIN_CONCAT_DETAIL(a, b) a ## b
 #define MIJIN_CONCAT(a, b) MIJIN_CONCAT_DETAIL(a, b)
 #define MIJIN_CONCAT3(a, b, c) MIJIN_CONCAT(a, MIJIN_CONCAT(b, c))
 
+#if MIJIN_COMPILER == MIJIN_COMPILER_GCC || MIJIN_COMPILER == MIJIN_COMPILER_CLANG
+#define MIJIN_FUNCNAME() __PRETTY_FUNCTION__
+#elif MIJIN_COMPILER == MIJIN_COMPILER_MSVC
+#define MIJIN_FUNCNAME() __FUNCSIG__
+#else
+#define MIJIN_FUNCNAME() __func__
+#endif
+
 #endif // defined(MIJIN_UTIL_COMMON_MACROS_HPP_INCLUDED)

source/mijin/util/formattable.hpp

@@ -0,0 +1,122 @@
+
+#pragma once
+
+#ifndef MIJIN_UTIL_FORMATTABLE_HPP_INCLUDED
+#define MIJIN_UTIL_FORMATTABLE_HPP_INCLUDED 1
+
+#include <format>
+#include "../container/boxed_object.hpp"
+
+namespace mijin
+{
+
+//
+// public concepts
+//
+
+template<typename T>
+concept parse_result_type = requires
+{
+    typename T::parse_result_t;
+};
+
+template<typename T, typename TParseContext>
+concept parseable_by_type = parse_result_type<T> &&
+        requires(const T& object, TParseContext& parseContext)
+{
+    { T::parseFormat(parseContext) } -> std::convertible_to<std::pair<typename TParseContext::iterator, typename T::parse_result_t>>;
+};
+
+template<typename T, typename TFmtContext>
+concept simple_formattable_to_type = requires(const T& object, TFmtContext& formatContext)
+{
+    { object.format(formatContext) } -> std::convertible_to<typename TFmtContext::iterator>;
+};
+
+template<typename T, typename TFmtContext, typename TParseContext>
+concept complex_formattable_to_type = parseable_by_type<T, TParseContext> &&
+        requires(const T& object, TParseContext& parseContext, TFmtContext& formatContext, T::parse_result_t& parseResult)
+{
+    { object.format(formatContext, parseResult) } -> std::convertible_to<typename TFmtContext::iterator>;
+};
+
+template<typename T, typename TFmtContext, typename TParseContext>
+concept formattable_to_type = simple_formattable_to_type<T, TFmtContext> || complex_formattable_to_type<T, TFmtContext, TParseContext>;
+
+template<typename T>
+concept cformattable_type = formattable_to_type<T, std::format_context, std::format_parse_context>;
+
+template<typename T>
+concept wformattable_type = formattable_to_type<T, std::wformat_context, std::wformat_parse_context>;
+
+template<typename T>
+concept formattable_type = cformattable_type<T> && wformattable_type<T>;
+
+template<typename T>
+concept any_formattable_type = cformattable_type<T> || wformattable_type<T>;
+
+//
+// internal types
+//
+
+namespace impl
+{
+template<typename T>
+struct ParseResult
+{
+};
+
+template<parse_result_type T>
+struct ParseResult<T>
+{
+    BoxedObject<typename T::parse_result_t> value;
+};
+}
+} // namespace mijin
+
+template<mijin::any_formattable_type T>
+struct std::formatter<T>
+{
+    [[no_unique_address]] [[maybe_unused]] mijin::impl::ParseResult<T> parseResult;
+
+    template<typename TContext>
+    constexpr TContext::iterator parse(TContext& ctx)
+    {
+        if constexpr (mijin::parse_result_type<T>)
+        {
+            static_assert(mijin::parseable_by_type<T, TContext>, "Type does not support parsing by this context.");
+            auto [it, result] = T::parseFormat(ctx);
+            parseResult.value.construct(std::move(result));
+            return it;
+        }
+        else
+        {
+            auto it = ctx.begin();
+            auto end = ctx.end();
+
+            if (it != end && *it != '}')
+            {
+                throw std::format_error("invalid format");
+            }
+
+            return it;
+        }
+    }
+
+    template<typename TContext>
+    TContext::iterator format(const T& object, TContext& ctx) const
+    {
+        if constexpr (mijin::parse_result_type<T>)
+        {
+            auto it = object.format(ctx, std::move(*parseResult.value));
+            parseResult.destroy();
+            return it;
+        }
+        else
+        {
+            static_assert(mijin::simple_formattable_to_type<T, TContext>, "Type does not support formatting to this context.");
+            return object.format(ctx);
+        }
+    }
+};
+#endif // MIJIN_UTIL_FORMATTABLE_HPP_INCLUDED

source/mijin/util/iterators.hpp

@@ -3,6 +3,7 @@
 #if !defined(MIJIN_UTIL_ITERATORS_HPP_INCLUDED)
 #define MIJIN_UTIL_ITERATORS_HPP_INCLUDED 1
 
+#include <array>
 #include <cstddef>
 #include <functional>
 #include <optional>
@@ -13,6 +14,7 @@
 #include <variant>
 #include "../container/optional.hpp"
 #include "../internal/common.hpp"
+#include "../util/annot.hpp"
 
 namespace mijin
 {
@@ -855,6 +857,64 @@ TAs collect(TIterable&& iterable)
     return TAs(iterable.begin(), iterable.end());
 }
 
+template<typename TEle, std::size_t numEles>
+class FixedArrayOutputIterator
+{
+public:
+    using array_t = std::array<TEle, numEles>;
+    using difference_type = std::ptrdiff_t;
+    using value_type = TEle;
+    using pointer = value_type*;
+    using reference = value_type&;
+
+    static constexpr std::size_t NUM_ELES = numEles;
+private:
+    not_null_t<array_t*> array_;
+    std::size_t counter_ = 0;
+public:
+    constexpr explicit FixedArrayOutputIterator(array_t& array) MIJIN_NOEXCEPT : array_(&array) {}
+    constexpr explicit FixedArrayOutputIterator(array_t& array, array_t::iterator pos) MIJIN_NOEXCEPT
+            : array_(&array), counter_(static_cast<std::size_t>(pos - array.begin())) {}
+    constexpr FixedArrayOutputIterator(const FixedArrayOutputIterator&) noexcept = default;
+
+    constexpr FixedArrayOutputIterator& operator=(const FixedArrayOutputIterator&) noexcept = default;
+
+    [[nodiscard]]
+    constexpr std::size_t getCounter() const MIJIN_NOEXCEPT
+    {
+        return counter_;
+    }
+
+    [[nodiscard]]
+    constexpr bool didOverflow() const MIJIN_NOEXCEPT
+    {
+        return counter_ >= NUM_ELES;
+    }
+
+    constexpr reference operator*() const MIJIN_NOEXCEPT
+    {
+        static TEle dummy_; // returned when we're at the end of the array
+        if (counter_ < NUM_ELES) {
+            return array_->at(counter_);
+        }
+        return dummy_;
+    }
+
+    constexpr FixedArrayOutputIterator& operator++() MIJIN_NOEXCEPT
+    {
+        ++counter_;
+        return *this;
+    }
+
+    constexpr FixedArrayOutputIterator operator++(int) const MIJIN_NOEXCEPT
+    {
+        FixedArrayOutputIterator copy(*this);
+        ++copy;
+        return copy;
+    }
+};
+static_assert(std::output_iterator<FixedArrayOutputIterator<int, 1>, int>);
+
 namespace pipe
 {
 template<typename T>
@@ -973,7 +1033,7 @@ auto operator|(TIterable&& iterable, Xth<idx>)
 {
     return map(std::forward<TIterable>(iterable), [](auto&& element) { return std::get<idx>(element); } );
 }
-}
+} // namespace pipe
 } // namespace mijin
 
 #endif // MIJIN_UTIL_ITERATORS_HPP_INCLUDED

source/mijin/util/os.cpp

@@ -10,6 +10,7 @@
     #include <mutex>
     #include <dlfcn.h>
     #include <pthread.h>
+    #include <time.h>
 #elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
     #include <array>
     #include <malloc.h>
@@ -38,12 +39,29 @@ namespace mijin
 // internal variables
 //
 
-#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
 namespace
 {
+#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
 std::mutex gDlErrorMutex; // dlerror may not be thread-safe
+
+const std::uint64_t gCPUClockResolution = []()
+{
+    struct timespec time;
+    [[maybe_unused]] const int result = clock_getres(CLOCK_PROCESS_CPUTIME_ID, &time);
+    MIJIN_ASSERT(result == 0, "Error getting cputime resolution.");
+    MIJIN_ASSERT(time.tv_sec == 0, "What kind of cpu clock is this?");
+    return static_cast<std::uint64_t>(time.tv_nsec);
+}();
+#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
+const std::uint64_t gCPUTickFrequency = []()
+{
+    LARGE_INTEGER ticks;
+    [[maybe_unused]] const BOOL result = QueryPerformanceFrequency(&ticks);
+    MIJIN_ASSERT(result, "Error getting cpu frequency.");
+    return static_cast<std::uint64_t>(ticks.QuadPart);
+}();
+#endif // MIJIN_TARGET_OS == MIJIN_OS_LINUX || MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
 }
-#endif // MIJIN_TARGET_OS == MIJIN_OS_LINUX
 
 //
 // internal functions
@@ -178,4 +196,27 @@ void alignedFree(void* ptr)
 #endif
 }
 
+std::uint64_t getCPUTicks() MIJIN_NOEXCEPT
+{
+#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
+    struct timespec time;
+    [[maybe_unused]] const int result = clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time);
+    MIJIN_ASSERT(result == 0, "Error getting cpu time.");
+    return (static_cast<std::uint64_t>(time.tv_sec) * 1e9 + time.tv_nsec) / gCPUClockResolution;
+#else
+    LARGE_INTEGER ticks;
+    [[maybe_unused]] const BOOL result = QueryPerformanceCounter(&ticks);
+    MIJIN_ASSERT(result, "Error getting cpu time.");
+    return static_cast<std::uint64_t>(ticks.QuadPart);
+#endif
+}
+
+std::uint64_t getCPUTicksPerSecond() MIJIN_NOEXCEPT
+{
+#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
+    return 1e9 / gCPUClockResolution;
+#else
+    return gCPUTickFrequency;
+#endif
+}
 } // namespace mijin

source/mijin/util/os.hpp

@@ -5,6 +5,7 @@
 #define MIJIN_UTIL_OS_HPP_INCLUDED 1
 
 #include <csignal>
+#include <cstdint>
 #include <string>
 #include <string_view>
 #include <utility>
@@ -85,6 +86,9 @@ void setCurrentThreadName(const char* threadName) MIJIN_NOEXCEPT;
 [[nodiscard]] void* alignedRealloc(void* ptr, std::size_t alignment, std::size_t size) MIJIN_NOEXCEPT;
 void alignedFree(void* ptr);
 
+[[nodiscard]] std::uint64_t getCPUTicks() MIJIN_NOEXCEPT;
+[[nodiscard]] std::uint64_t getCPUTicksPerSecond() MIJIN_NOEXCEPT;
+
 SharedLibrary::~SharedLibrary() MIJIN_NOEXCEPT
 {
     close();

source/mijin/util/traits.hpp

@@ -253,6 +253,42 @@ struct optional_base<T, false>
 template<typename T, bool enable>
 using optional_base_t = optional_base<T, enable>::type;
 
+namespace impl
+{
+template<typename TFunc>
+struct function_traits_base {};
+
+template<typename TResult, typename... TParams>
+struct function_traits_base<TResult (*)(TParams...)>
+{
+    using result_t = TResult;
+    using params_t = std::tuple<TParams...>;
+};
+
+template<typename TResult, typename TType, typename... TParams>
+struct function_traits_base<TResult (TType::*)(TParams...)>
+{
+    using result_t = TResult;
+    using params_t = std::tuple<TType*, TParams...>;
+};
+
+template<typename TResult, typename TType, typename... TParams>
+struct function_traits_base<TResult (TType::*)(TParams...) const>
+{
+    using result_t = TResult;
+    using params_t = std::tuple<const TType*, TParams...>;
+};
+}
+
+template<typename TFunc>
+struct function_traits : impl::function_traits_base<TFunc>
+{
+    static constexpr std::size_t NUM_PARAMS = std::tuple_size_v<typename impl::function_traits_base<TFunc>::params_t>;
+
+    template<std::size_t pos>
+    using param_t = std::tuple_element_t<pos, typename impl::function_traits_base<TFunc>::params_t>;
+};
+
 //
 // public functions
 //

source/mijin/util/variant.hpp

@@ -4,6 +4,7 @@
 #if !defined(MIJIN_UTIL_VARIANT_HPP_INCLUDED)
 #define MIJIN_UTIL_VARIANT_HPP_INCLUDED 1
 
+#include <utility>
 #include <variant>
 #include "./traits.hpp"
 
@@ -23,10 +24,21 @@ inline constexpr bool variant_contains_v<TSearch, std::variant<TVariantTypes...>
 //
 // public types
 //
+
 template<typename... TCallable>
 struct Visitor : TCallable ...
 {
     using TCallable::operator()...;
 };
+
+template<typename TRet>
+struct CastTo
+{
+    template<typename T>
+    TRet operator()(T&& arg) const
+    {
+        return static_cast<TRet>(std::forward<T>(arg));
+    }
+};
 }
 #endif // !defined(MIJIN_UTIL_VARIANT_HPP_INCLUDED)

source/mijin/util/winundef.hpp

@@ -26,3 +26,7 @@
 #if defined(DEBUG)
 #undef DEBUG
 #endif
+
+#if defined(VOID)
+#undef VOID
+#endif

source/mijin/virtual_filesystem/filesystem.cpp

@@ -3,6 +3,10 @@
 
 #include "../platform/folders.hpp"
 
+#include <filesystem>
+
+namespace fs = std::filesystem;
+
 namespace mijin
 {
 
@@ -26,100 +30,91 @@ namespace mijin
 // internal functions
 //
 
+namespace
+{
+void doGetFileInfo(const fs::path& stlPath, FileInfo& outInfo)
+{
+    std::error_code err;
+
+    outInfo.isFolder = fs::is_directory(stlPath, err);
+    outInfo.isSymlink = fs::is_symlink(stlPath, err);
+    outInfo.isSpecial = !outInfo.isFolder && !fs::is_regular_file(stlPath, err);
+    outInfo.isHidden = stlPath.c_str()[0] == '.'; // at least for Linux
+    if (outInfo.isFolder)
+    {
+        const fs::directory_iterator dirIt(stlPath, err);
+        if (err != std::error_code{})
+        {
+            outInfo.size = std::distance(dirIt, fs::directory_iterator());
+        }
+        else
+        {
+            outInfo.size = 0;
+        }
+    }
+    else if (!outInfo.isSpecial)
+    {
+        outInfo.size = fs::file_size(stlPath, err);
+        if (err)
+        {
+            outInfo.size = 0;
+        }
+    }
+}
+}
+
 //
 // public functions
 //
 
-fs::path OSFileSystemAdapter::getHomeFolder()
+std::vector<FolderEntry> OSFileSystemAdapter::listFiles(PathView folder)
 {
-    return getKnownFolder(KnownFolder::USER_HOME);
-}
-
-std::vector<FileInfo> OSFileSystemAdapter::listFiles(const fs::path& folder)
-{
-    std::vector<FileInfo> entries;
+    std::vector<FolderEntry> entries;
     std::error_code err;
-    const fs::directory_iterator iterator(folder, fs::directory_options::skip_permission_denied, err);
+
+    const fs::path stlFolder(folder.stringView());
+    const fs::directory_iterator iterator(stlFolder, fs::directory_options::skip_permission_denied, err);
     if (err) {
         return {}; // TODO: propagate?
     }
-    for (const fs::directory_entry& entry : iterator)
+    for (const fs::directory_entry& stlEntry : iterator)
     {
-        FileInfo& info = entries.emplace_back();
-        info.path = entry.path();
-        info.exists = true;
-        info.isFolder = entry.is_directory(err);
-        info.isSymlink = entry.is_symlink(err);
-        info.isSpecial = !info.isFolder && !entry.is_regular_file(err);
-        info.isHidden = info.path.filename().string().starts_with('.'); // at least for Linux
-        if (info.isFolder)
-        {
-            std::error_code errorCode;
-            fs::directory_iterator dirIt(info.path, errorCode);
-            if (errorCode != std::error_code{})
-            {
-                info.size = std::distance(dirIt, fs::directory_iterator());
-            }
-            else
-            {
-                info.size = 0;
-            }
-        }
-        else if (!info.isSpecial)
-        {
-            info.size = entry.file_size(err);
-            if (err)
-            {
-                info.size = 0;
-            }
-        }
+        FolderEntry& entry = entries.emplace_back();
+        entry.path = stlEntry.path().generic_string();
+        entry.info.exists = true;
+        doGetFileInfo(stlEntry.path(), entry.info);
     }
     return entries;
 }
 
-FileInfo OSFileSystemAdapter::getFileInfo(const fs::path& file)
+FileInfo OSFileSystemAdapter::getFileInfo(PathView file)
 {
+    const fs::path stlFile(file.stringView());
+
     FileInfo info = {};
     std::error_code err;
-    info.path = file;
-    info.exists = fs::exists(file, err);
+    info.exists = fs::exists(stlFile, err);
     if (info.exists)
     {
-        info.isFolder = fs::is_directory(file, err);
-        info.isSymlink = fs::is_symlink(file, err);
-        info.isSpecial = !info.isFolder && !fs::is_regular_file(file, err);
-        info.isHidden = info.path.filename().string().starts_with('.'); // at least for Linux
-        if (info.isFolder) {
-            MIJIN_TRY
-            {
-                info.size = std::distance(fs::directory_iterator(info.path), fs::directory_iterator());
-            }
-            MIJIN_CATCH(std::runtime_error&)
-            {
-                info.size = 0;
-            }
-        }
-        else if (!info.isSpecial)
-        {
-            info.size = fs::file_size(file, err);
-            if (err) {
-                info.size = 0;
-            }
-        }
+        doGetFileInfo(fs::path(file.stringView()), info);
     }
     return info;
 }
 
-Optional<fs::path> OSFileSystemAdapter::getNativePath(const fs::path& file)
+Optional<NativePath> OSFileSystemAdapter::getNativePath(PathView file)
 {
-    return file;
+    return NativePath(file);
 }
 
-StreamError OSFileSystemAdapter::open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
+StreamError OSFileSystemAdapter::open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
 {
-    const std::string pathStr = path.string();
+    const PathView::string_view_t pathSv = path.stringView();
+    char* pathStr = static_cast<char*>(alloca(pathSv.size() + 1));
+    std::memcpy(pathStr, pathSv.data(), pathSv.size());
+    pathStr[pathSv.size()] = '\0';
+
     auto stream = std::make_unique<FileStream>();
-    const StreamError error = stream->open(pathStr.c_str(), mode);
+    const StreamError error = stream->open(pathStr, mode);
     if (error != StreamError::SUCCESS) {
         return error;
     }

source/mijin/virtual_filesystem/filesystem.hpp

@@ -6,17 +6,15 @@
 
 #include <array>
 #include <cmath>
-#include <filesystem>
 #include <sstream>
 #include <string>
 #include <vector>
 #include "../container/optional.hpp"
 #include "../io/stream.hpp"
 #include "../internal/common.hpp"
+#include "../types/path.hpp"
 #include "../util/hash.hpp"
 
-namespace fs = std::filesystem;
-
 namespace mijin
 {
 
@@ -34,7 +32,6 @@ namespace mijin
 
 struct FileInfo
 {
-    fs::path path;
     /// either file size in bytes, or number of entries if folder
     std::size_t size = 0;
     bool exists : 1 = false;
@@ -44,17 +41,23 @@ struct FileInfo
     bool isHidden : 1 = false;
 };
 
+struct FolderEntry
+{
+    Path path;
+    FileInfo info;
+};
+
 // basically just a thin wrapper around adapter + path, for utility
 class PathReference
 {
 private:
     class FileSystemAdapter* adapter_ = nullptr;
-    fs::path path_ = {};
+    Path path_ = {};
 public:
     PathReference() = default;
     PathReference(const PathReference&) = default;
     PathReference(PathReference&&) = default;
-    PathReference(class FileSystemAdapter* adapter, fs::path path) MIJIN_NOEXCEPT : adapter_(adapter), path_(std::move(path)) {}
+    PathReference(class FileSystemAdapter* adapter, Path path) MIJIN_NOEXCEPT : adapter_(adapter), path_(std::move(path)) {}
 
     PathReference& operator=(const PathReference&) = default;
     PathReference& operator=(PathReference&&) MIJIN_NOEXCEPT = default;
@@ -63,13 +66,13 @@ public:
 
     [[nodiscard]] bool empty() const MIJIN_NOEXCEPT { return adapter_ == nullptr; }
     [[nodiscard]] class FileSystemAdapter* getAdapter() const noexcept { return adapter_; }
-    [[nodiscard]] const fs::path& getPath() const MIJIN_NOEXCEPT { return path_; }
+    [[nodiscard]] const Path& getPath() const MIJIN_NOEXCEPT { return path_; }
     [[nodiscard]] inline FileInfo getInfo() const;
-    [[nodiscard]] inline Optional<fs::path> getNativePath() const;
+    [[nodiscard]] inline Optional<NativePath> getNativePath() const;
     [[nodiscard]] inline StreamError open(FileOpenMode mode, std::unique_ptr<Stream>& outStream) const;
 
     [[nodiscard]]
-    PathReference operator/(const fs::path& more) const
+    PathReference operator/(const Path& more) const
     {
         return PathReference(adapter_, path_ / more);
     }
@@ -80,16 +83,14 @@ class FileSystemAdapter
 public:
     virtual ~FileSystemAdapter() = default;
 
-    [[deprecated("Will be removed ASAP")]]
-    [[nodiscard]] virtual fs::path getHomeFolder() { return {}; } // TODO: get rid of this ...
-    [[nodiscard]] virtual std::vector<FileInfo> listFiles(const fs::path& folder) = 0;
-    [[nodiscard]] virtual FileInfo getFileInfo(const fs::path& file) = 0;
-    [[nodiscard]] virtual Optional<fs::path> getNativePath(const fs::path& /* file */) { return NULL_OPTIONAL; }
-    [[nodiscard]] virtual StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) = 0;
-    virtual void getAllPaths(const fs::path& path, std::vector<PathReference>& outPaths) { outPaths.push_back(getPath(path)); }
+    [[nodiscard]] virtual std::vector<FolderEntry> listFiles(PathView folder) = 0;
+    [[nodiscard]] virtual FileInfo getFileInfo(PathView file) = 0;
+    [[nodiscard]] virtual Optional<NativePath> getNativePath(PathView /* file */) { return NULL_OPTIONAL; }
+    [[nodiscard]] virtual StreamError open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) = 0;
+    virtual void getAllPaths(PathView path, std::vector<PathReference>& outPaths) { outPaths.push_back(getPath(Path(path))); }
 
-    [[nodiscard]] PathReference getPath(fs::path path) MIJIN_NOEXCEPT { return PathReference(this, std::move(path)); }
-    [[nodiscard]] std::vector<PathReference> getAllPaths(const fs::path& path)
+    [[nodiscard]] PathReference getPath(Path path) MIJIN_NOEXCEPT { return PathReference(this, std::move(path)); }
+    [[nodiscard]] std::vector<PathReference> getAllPaths(PathView path)
     {
         std::vector<PathReference> paths;
         getAllPaths(path, paths);
@@ -100,11 +101,10 @@ public:
 class OSFileSystemAdapter : public FileSystemAdapter
 {
 public:
-    fs::path getHomeFolder() override;
-    std::vector<FileInfo> listFiles(const fs::path& folder) override;
-    FileInfo getFileInfo(const fs::path& file) override;
-    Optional<fs::path> getNativePath(const fs::path& file) override;
-    StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
+    std::vector<FolderEntry> listFiles(PathView folder) override;
+    FileInfo getFileInfo(PathView file) override;
+    Optional<NativePath> getNativePath(PathView file) override;
+    StreamError open(PathView, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
 
     static OSFileSystemAdapter& getInstance();
 };
@@ -118,7 +118,7 @@ inline FileInfo PathReference::getInfo() const
     return adapter_->getFileInfo(path_);
 }
 
-Optional<fs::path> PathReference::getNativePath() const
+Optional<NativePath> PathReference::getNativePath() const
 {
     return adapter_->getNativePath(path_);
 }

source/mijin/virtual_filesystem/memory.cpp

@@ -5,30 +5,31 @@
 
 namespace mijin
 {
-std::vector<FileInfo> MemoryFileSystemAdapter::listFiles(const fs::path& folder)
+std::vector<FolderEntry> MemoryFileSystemAdapter::listFiles(PathView folder)
 {
     const detail::MemoryFolder* folderObj = findFolder(folder);
     if (folderObj == nullptr)
     {
         return {};
     }
-    std::vector<FileInfo> result;
+    std::vector<FolderEntry> result;
     result.reserve(folderObj->folders.size() + folderObj->files.size());
 
+    const Path folderPath(folder);
     for (const auto& [name, subFolder] : folderObj->folders)
     {
-        result.push_back(folderInfo(folder / name, subFolder));
+        result.emplace_back(folderPath / name, folderInfo(subFolder));
     }
 
     for (const auto& [name, file] : folderObj->files)
     {
-        result.push_back(fileInfo(folder / name, file));
+        result.emplace_back(folderPath / name, fileInfo(file));
     }
 
     return result;
 }
 
-FileInfo MemoryFileSystemAdapter::getFileInfo(const fs::path& file)
+FileInfo MemoryFileSystemAdapter::getFileInfo(PathView file)
 {
 #if 0 // shouldn't be necessary
     // empty means root
@@ -43,38 +44,38 @@ FileInfo MemoryFileSystemAdapter::getFileInfo(const fs::path& file)
     }
 #endif
 
-    const detail::MemoryFolder* folderObj = findFolder(file.parent_path());
+    const detail::MemoryFolder* folderObj = findFolder(file.getParent());
     if (folderObj == nullptr)
     {
         return {};
     }
-    const std::string filename = file.filename().generic_string();
+    const std::string_view filename = file.getName();
 
     if (auto itFolder = folderObj->folders.find(filename); itFolder != folderObj->folders.end())
     {
-        return folderInfo(file, itFolder->second);
+        return folderInfo(itFolder->second);
     }
     if (auto itFile = folderObj->files.find(filename); itFile != folderObj->files.end())
     {
-        return fileInfo(file, itFile->second);
+        return fileInfo(itFile->second);
     }
     return {};
 }
 
-StreamError MemoryFileSystemAdapter::open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
+StreamError MemoryFileSystemAdapter::open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
 {
     if (mode != FileOpenMode::READ)
     {
         return StreamError::IO_ERROR;
     }
 
-    const detail::MemoryFolder* folderObj = findFolder(path.parent_path());
+    const detail::MemoryFolder* folderObj = findFolder(path.getParent());
     if (folderObj == nullptr)
     {
         return StreamError::IO_ERROR;
     }
 
-    auto itFile = folderObj->files.find(path.filename().generic_string());
+    auto itFile = folderObj->files.find(path.getName());
     if (itFile == folderObj->files.end())
     {
         return StreamError::IO_ERROR;
@@ -87,10 +88,10 @@ StreamError MemoryFileSystemAdapter::open(const fs::path& path, FileOpenMode mod
     return StreamError::SUCCESS;
 }
 
-bool MemoryFileSystemAdapter::addFile(const fs::path& path, std::span<const std::uint8_t> data, Overwrite overwrite, CopyData copyData)
+bool MemoryFileSystemAdapter::addFile(PathView path, std::span<const std::uint8_t> data, Overwrite overwrite, CopyData copyData)
 {
-    detail::MemoryFolder& folder = *findFolder(path.parent_path(), true);
-    std::string filename = path.filename().generic_string();
+    detail::MemoryFolder& folder = *findFolder(path.getParent(), true);
+    const std::string_view filename = path.getName();
 
     if (folder.folders.contains(filename))
     {
@@ -107,29 +108,28 @@ bool MemoryFileSystemAdapter::addFile(const fs::path& path, std::span<const std:
         data = fileData_.emplace_back(data.begin(), data.end());
     }
 
-    folder.files.emplace(std::move(filename), detail::MemoryFile{.data = data});
+    folder.files.emplace(filename, detail::MemoryFile{.data = data});
     return true;
 }
 
-void MemoryFileSystemAdapter::addFolder(const fs::path& path)
+void MemoryFileSystemAdapter::addFolder(PathView path)
 {
     (void) findFolder(path, true);
 }
 
-detail::MemoryFolder* MemoryFileSystemAdapter::findFolder(const fs::path& path, bool create) MIJIN_NOEXCEPT
+detail::MemoryFolder* MemoryFileSystemAdapter::findFolder(PathView path, bool create) MIJIN_NOEXCEPT
 {
     detail::MemoryFolder* folder = &root_;
-    for (const fs::path& part : path)
+    for (const std::string_view part : path)
     {
-        std::string partname = part.generic_string();
-        auto it = folder->folders.find(partname);
+        auto it = folder->folders.find(part);
         if (it == folder->folders.end())
         {
             if (!create)
             {
                 return nullptr;
             }
-            folder = &folder->folders[std::move(partname)];
+            folder = &folder->folders[std::string(part)];
         }
         else
         {
@@ -139,20 +139,18 @@ detail::MemoryFolder* MemoryFileSystemAdapter::findFolder(const fs::path& path,
     return folder;
 }
 
-FileInfo MemoryFileSystemAdapter::folderInfo(const fs::path& path, const detail::MemoryFolder& folder) const MIJIN_NOEXCEPT
+FileInfo MemoryFileSystemAdapter::folderInfo(const detail::MemoryFolder& folder) const MIJIN_NOEXCEPT
 {
     return {
-        .path = path,
         .size = folder.folders.size() + folder.files.size(),
         .exists = true,
         .isFolder = true
     };
 }
 
-FileInfo MemoryFileSystemAdapter::fileInfo(const fs::path& path, const detail::MemoryFile& file) const MIJIN_NOEXCEPT
+FileInfo MemoryFileSystemAdapter::fileInfo(const detail::MemoryFile& file) const MIJIN_NOEXCEPT
 {
     return {
-        .path = path,
         .size = file.data.size(),
         .exists = true
     };

source/mijin/virtual_filesystem/memory.hpp

@@ -35,20 +35,20 @@ private:
     detail::MemoryFolder root_;
     std::vector<std::vector<std::uint8_t>> fileData_;
 public:
-    [[nodiscard]] std::vector<FileInfo> listFiles(const fs::path& folder) override;
-    [[nodiscard]] FileInfo getFileInfo(const fs::path& file) override;
-    [[nodiscard]] StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
+    [[nodiscard]] std::vector<FolderEntry> listFiles(PathView folder) override;
+    [[nodiscard]] FileInfo getFileInfo(PathView file) override;
+    [[nodiscard]] StreamError open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
 
-    bool addFile(const fs::path& path, std::span<const std::uint8_t> data, Overwrite overwrite = Overwrite::NO, CopyData copyData = CopyData::NO);
-    bool addFile(const fs::path& path, std::span<const std::uint8_t> data, CopyData copyData)
+    bool addFile(PathView path, std::span<const std::uint8_t> data, Overwrite overwrite = Overwrite::NO, CopyData copyData = CopyData::NO);
+    bool addFile(PathView path, std::span<const std::uint8_t> data, CopyData copyData)
     {
         return addFile(path, data, Overwrite::NO, copyData);
     }
-    void addFolder(const fs::path& path);
+    void addFolder(PathView path);
 private:
-    detail::MemoryFolder* findFolder(const fs::path& path, bool create = false) MIJIN_NOEXCEPT;
-    FileInfo folderInfo(const fs::path& path, const detail::MemoryFolder& folder) const MIJIN_NOEXCEPT;
-    FileInfo fileInfo(const fs::path& path, const detail::MemoryFile& file) const MIJIN_NOEXCEPT;
+    detail::MemoryFolder* findFolder(PathView path, bool create = false) MIJIN_NOEXCEPT;
+    FileInfo folderInfo(const detail::MemoryFolder& folder) const MIJIN_NOEXCEPT;
+    FileInfo fileInfo(const detail::MemoryFile& file) const MIJIN_NOEXCEPT;
 };
 } // namespace mijin
 

source/mijin/virtual_filesystem/relative.hpp

@@ -27,10 +27,10 @@ class RelativeFileSystemAdapter : public FileSystemAdapter
 {
 private:
     TWrapped wrapped_;
-    fs::path root_;
+    Path root_;
 public:
     template<typename... TArgs>
-    explicit RelativeFileSystemAdapter(fs::path root, TArgs&&... args)
+    explicit RelativeFileSystemAdapter(Path root, TArgs&&... args)
         : wrapped_(std::forward<TArgs>(args)...), root_(std::move(root)) {}
     RelativeFileSystemAdapter(const RelativeFileSystemAdapter&) = default;
     RelativeFileSystemAdapter(RelativeFileSystemAdapter&&) MIJIN_NOEXCEPT = default;
@@ -38,13 +38,12 @@ public:
     RelativeFileSystemAdapter& operator=(const RelativeFileSystemAdapter&) = default;
     RelativeFileSystemAdapter& operator=(RelativeFileSystemAdapter&&) MIJIN_NOEXCEPT = default;
 
-    fs::path getHomeFolder() override;
-    std::vector<FileInfo> listFiles(const fs::path& folder) override;
-    FileInfo getFileInfo(const fs::path& file) override;
-    Optional<fs::path> getNativePath(const fs::path& file) override;
-    StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
+    std::vector<FolderEntry> listFiles(PathView folder) override;
+    FileInfo getFileInfo(PathView file) override;
+    Optional<NativePath> getNativePath(PathView file) override;
+    StreamError open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
 private:
-    fs::path appendPath(const fs::path& other) const MIJIN_NOEXCEPT;
+    Path appendPath(PathView other) const MIJIN_NOEXCEPT;
 };
 
 //
@@ -52,51 +51,44 @@ private:
 //
 
 template<typename TWrapped>
-fs::path RelativeFileSystemAdapter<TWrapped>::getHomeFolder()
+std::vector<FolderEntry> RelativeFileSystemAdapter<TWrapped>::listFiles(PathView folder)
 {
-    return root_;
-}
-
-template<typename TWrapped>
-std::vector<FileInfo> RelativeFileSystemAdapter<TWrapped>::listFiles(const fs::path& folder)
-{
-    std::vector<FileInfo> result;
+    std::vector<FolderEntry> result;
 
     result = wrapped_.listFiles(appendPath(folder));
-    for (FileInfo& fileInfo : result) {
-        fileInfo.path = "/" / fileInfo.path.lexically_relative(root_);
+    for (FolderEntry& fileInfo : result) {
+        fileInfo.path = Path("/") / fileInfo.path.stringView().substr(root_.size());
     }
     return result;
 }
 
 template<typename TWrapped>
-FileInfo RelativeFileSystemAdapter<TWrapped>::getFileInfo(const fs::path& file)
+FileInfo RelativeFileSystemAdapter<TWrapped>::getFileInfo(PathView file)
 {
     return wrapped_.getFileInfo(appendPath(file));
 }
 
 template<typename TWrapped>
-Optional<fs::path> RelativeFileSystemAdapter<TWrapped>::getNativePath(const fs::path& file)
+Optional<NativePath> RelativeFileSystemAdapter<TWrapped>::getNativePath(PathView file)
 {
     return wrapped_.getNativePath(appendPath(file));
 }
 
 template<typename TWrapped>
-StreamError RelativeFileSystemAdapter<TWrapped>::open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
+StreamError RelativeFileSystemAdapter<TWrapped>::open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
 {
     return wrapped_.open(appendPath(path), mode, outStream);
 }
 
 template<typename TWrapped>
-fs::path RelativeFileSystemAdapter<TWrapped>::appendPath(const fs::path& other) const MIJIN_NOEXCEPT
+Path RelativeFileSystemAdapter<TWrapped>::appendPath(PathView other) const MIJIN_NOEXCEPT
 {
-    fs::path combinedPath = root_;
-    if (other.is_absolute()) {
-        combinedPath += other;
-    }
-    else {
-        combinedPath /= other;
+    Path combinedPath = root_;
+    std::string_view otherSv(other.stringView());
+    if (!otherSv.empty() && otherSv[0] == Path::SEPARATOR) {
+        otherSv = otherSv.substr(1);
     }
+    combinedPath /= otherSv;
     return combinedPath;
 }
 
@@ -105,7 +97,7 @@ namespace vfs_pipe
 template<typename TBase>
 struct RelativeBuilder : Builder<RelativeBuilder<TBase>, RelativeFileSystemAdapter<typename TBase::adapter_t>>
 {
-    fs::path root;
+    Path root;
     TBase base;
 
     std::unique_ptr<RelativeFileSystemAdapter<typename TBase::adapter_t>> build()
@@ -116,11 +108,11 @@ struct RelativeBuilder : Builder<RelativeBuilder<TBase>, RelativeFileSystemAdapt
 
 struct RelativeOptions
 {
-    fs::path root;
+    Path root;
 };
 
 [[nodiscard]]
-inline RelativeOptions relative_to(fs::path root) noexcept
+inline RelativeOptions relative_to(Path root) noexcept
 {
     return {.root = std::move(root) };
 }

source/mijin/virtual_filesystem/stacked.cpp

@@ -31,40 +31,20 @@ namespace mijin
 // public functions
 //
 
-fs::path StackedFileSystemAdapter::getHomeFolder()
+std::vector<FolderEntry> StackedFileSystemAdapter::listFiles(PathView folder)
 {
-    if (adapters_.empty()) {
-        return fs::path();
-    }
-#if MIJIN_COMPILER == MIJIN_COMPILER_MSVC
-#pragma warning(push)
-#pragma warning(disable : 4996) // yeah, we're using a deprecated function here, in order to implement another deprecated function ¯\_(ツ)_/¯
-#elif MIJIN_COMPILER == MIJIN_COMPILER_GCC || MIJIN_COMPILER == MIJIN_COMPILER_CLANG
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#endif
-    return adapters_.front()->getHomeFolder();
-#if MIJIN_COMPILER == MIJIN_COMPILER_MSVC
-#pragma warning(pop)
-#elif MIJIN_COMPILER == MIJIN_COMPILER_GCC || MIJIN_COMPILER == MIJIN_COMPILER_CLANG
-#pragma GCC diagnostic pop
-#endif
-}
-
-std::vector<FileInfo> StackedFileSystemAdapter::listFiles(const fs::path& folder)
-{
-    std::vector<FileInfo> files;
+    std::vector<FolderEntry> files;
 
     for (auto& adapter : adapters_)
     {
-        for (const FileInfo& file : adapter->listFiles(folder))
+        for (const FolderEntry& entry : adapter->listFiles(folder))
         {
-            auto it = std::find_if(files.begin(), files.end(), [&](const FileInfo& existing)
+            auto it = std::ranges::find_if(files, [&](const FolderEntry& existing)
             {
-                return existing.path == file.path;
+                return existing.path == entry.path;
             });
             if (it == files.end()) {
-                files.push_back(file);
+                files.push_back(entry);
             }
         }
     }
@@ -72,7 +52,7 @@ std::vector<FileInfo> StackedFileSystemAdapter::listFiles(const fs::path& folder
     return files;
 }
 
-FileInfo StackedFileSystemAdapter::getFileInfo(const fs::path& file)
+FileInfo StackedFileSystemAdapter::getFileInfo(PathView file)
 {
     for (auto& adapter : adapters_)
     {
@@ -85,11 +65,11 @@ FileInfo StackedFileSystemAdapter::getFileInfo(const fs::path& file)
     return {};
 }
 
-Optional<fs::path> StackedFileSystemAdapter::getNativePath(const fs::path& file)
+Optional<NativePath> StackedFileSystemAdapter::getNativePath(PathView file)
 {
     for (auto& adapter : adapters_)
     {
-        Optional<fs::path> result = adapter->getNativePath(file);
+        Optional<NativePath> result = adapter->getNativePath(file);
         if (!result.empty())
         {
             return result;
@@ -98,7 +78,7 @@ Optional<fs::path> StackedFileSystemAdapter::getNativePath(const fs::path& file)
     return NULL_OPTIONAL;
 }
 
-StreamError StackedFileSystemAdapter::open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
+StreamError StackedFileSystemAdapter::open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream)
 {
     // try to open existing files first
     for (auto& adapter : adapters_)
@@ -125,7 +105,7 @@ StreamError StackedFileSystemAdapter::open(const fs::path& path, FileOpenMode mo
     return StreamError::IO_ERROR;
 }
 
-void StackedFileSystemAdapter::getAllPaths(const fs::path& path, std::vector<PathReference>& outPaths)
+void StackedFileSystemAdapter::getAllPaths(PathView path, std::vector<PathReference>& outPaths)
 {
     for (auto& adapter : adapters_)
     {

source/mijin/virtual_filesystem/stacked.hpp

@@ -28,12 +28,11 @@ class StackedFileSystemAdapter : public FileSystemAdapter
 private:
     std::vector<std::unique_ptr<FileSystemAdapter>> adapters_;
 public:
-    fs::path getHomeFolder() override;
-    std::vector<FileInfo> listFiles(const fs::path& folder) override;
-    FileInfo getFileInfo(const fs::path& file) override;
-    Optional<fs::path> getNativePath(const fs::path& file) override;
-    StreamError open(const fs::path& path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
-    void getAllPaths(const fs::path &path, std::vector<PathReference> &outPaths) override;
+    std::vector<FolderEntry> listFiles(PathView folder) override;
+    FileInfo getFileInfo(PathView file) override;
+    Optional<NativePath> getNativePath(PathView file) override;
+    StreamError open(PathView path, FileOpenMode mode, std::unique_ptr<Stream>& outStream) override;
+    void getAllPaths(PathView path, std::vector<PathReference> &outPaths) override;
     using FileSystemAdapter::getAllPaths;
 
     inline FileSystemAdapter* addAdapter(std::unique_ptr<FileSystemAdapter>&& adapter) {