Added zip() functionality for combining iterators.

source/mijin/async/future.hpp

@@ -34,21 +34,21 @@ namespace impl
 template<typename TValue>
 struct FutureStorage
 {
-    std::optional<TValue> value;
+    Optional<TValue> value;
 
     void setValue(TValue value_) noexcept { value = std::move(value_); }
-    [[nodiscard]] TValue& getValue() noexcept { return value.value(); }
+    [[nodiscard]] TValue& getValue() noexcept { return value.get(); }
 
 };
 
-template<typename TValue>
+// template<typename TValue>
-struct FutureStorage<TValue&>
+// struct FutureStorage<TValue&>
-{
+// {
-    std::optional<TValue*> value;
+//     Optional<TValue*> value;
-
+//
-    void setValue(TValue& value_) noexcept { value = &value_; }
+//     void setValue(TValue& value_) noexcept { value = &value_; }
-    [[nodiscard]] TValue& getValue() const noexcept { return *value.value(); }
+//     [[nodiscard]] TValue& getValue() const noexcept { return *value.get(); }
-};
+// };
 
 template<>
 struct FutureStorage<void>

source/mijin/container/optional.hpp

@@ -173,7 +173,12 @@ Optional<TValue>::Optional(Optional&& other) noexcept
 {
     if (other)
     {
+        if constexpr (!std::is_reference_v<TValue>) {
             emplace(std::move(other.get()));
+        }
+        else {
+            emplace(other.get());
+        }
         other.reset();
     }
 }

source/mijin/debug/stacktrace.hpp

@@ -7,6 +7,9 @@
 #include <cmath>
 #include <iomanip>
 #include <vector>
+#if __has_include(<fmt/format.h>)
+#   include <fmt/format.h>
+#endif
 #include "./symbol_info.hpp"
 #include "../types/result.hpp"
 #include "../util/iterators.hpp"
@@ -82,4 +85,56 @@ TStream& operator<<(TStream& stream, const Stacktrace& stacktrace)
 
 } // namespace mijin
 
+#if __has_include(<fmt/format.h>)
+template<>
+struct fmt::formatter<mijin::Stackframe>
+{
+    constexpr auto parse(format_parse_context& ctx) -> decltype(ctx.begin())
+    {
+        auto it = ctx.begin();
+        auto end = ctx.end();
+
+        if (it != end && *it != '}') throw format_error("invalid format");
+
+        return it;
+    }
+
+    template<typename TContext>
+    auto format(const mijin::Stackframe& stackframe, TContext& ctx) const -> decltype(ctx.out())
+    {
+        auto it = ctx.out();
+        it = fmt::format_to(it, "[{}] {}:{} in {}", stackframe.address, stackframe.filename,
+                            stackframe.lineNumber, mijin::demangleCPPIdentifier(stackframe.function.c_str()));
+        return it;
+    }
+};
+
+template<>
+struct fmt::formatter<mijin::Stacktrace>
+{
+    constexpr auto parse(format_parse_context& ctx) -> decltype(ctx.begin())
+    {
+        auto it = ctx.begin();
+        auto end = ctx.end();
+
+        if (it != end && *it != '}') throw format_error("invalid format");
+
+        return it;
+    }
+
+    template<typename TContext>
+    auto format(const mijin::Stacktrace& stacktrace, TContext& ctx) const -> decltype(ctx.out())
+    {
+        const int numDigits = static_cast<int>(std::ceil(std::log10(stacktrace.getFrames().size())));
+        auto it = ctx.out();
+        it = fmt::format_to(it, "[{} frames]", stacktrace.getFrames().size());
+        for (const auto& [idx, frame] : mijin::enumerate(stacktrace.getFrames()))
+        {
+            it = fmt::format_to(it, "\n  #{:<{}} at {}", idx, numDigits, frame);
+        }
+        return it;
+    }
+};
+#endif // __has_include(<fmt/format.h>)
+
 #endif // !defined(MIJIN_DEBUG_STACKTRACE_HPP_INCLUDED)

source/mijin/util/iterators.hpp

@@ -169,6 +169,86 @@ Enumeratable<TIdx, TIterable> enumerate(TIterable&& iterable)
     return {.base = {std::forward<TIterable>(iterable)}};
 }
 
+template<typename TFirstIterator, typename TSecondIterator>
+struct ZippingIterator
+{
+    TFirstIterator first;
+    TSecondIterator second;
+
+    ZippingIterator(TFirstIterator first_, TSecondIterator second_) noexcept : first(first_), second(second_) {}
+    ZippingIterator(const ZippingIterator&) noexcept = default;
+
+    ZippingIterator& operator=(const ZippingIterator&) noexcept = default;
+
+    auto operator*() const noexcept
+    {
+        return std::tie(*first, *second);
+    }
+
+    ZippingIterator& operator++() noexcept
+    {
+        ++first;
+        ++second;
+        return *this;
+    }
+
+    ZippingIterator operator++(int) noexcept
+    {
+        ZippingIterator copy(*this);
+        ++(*this);
+        return copy;
+    }
+
+    ZippingIterator& operator--() noexcept
+    {
+        --first;
+        --second;
+        return *this;
+    }
+
+    ZippingIterator operator--(int) noexcept
+    {
+        ZippingIterator copy(*this);
+        --(*this);
+        return copy;
+    }
+
+    bool operator==(const ZippingIterator& other) const noexcept
+    {
+        return first == other.first || second == other.second; // note: this uses or so reaching the end on one range also ends the zipped one.
+    }
+
+    bool operator!=(const ZippingIterator& other) const noexcept
+    {
+        return !(*this == other);
+    }
+};
+template<typename TFirstIterator, typename TSecondIterator>
+ZippingIterator(TFirstIterator, TSecondIterator) -> ZippingIterator<TFirstIterator, TSecondIterator>;
+
+template<typename TFirst, typename TSecond>
+struct ZippingRange : RangeAdapter
+{
+    RangeRef<TFirst> first;
+    RangeRef<TSecond> second;
+
+    auto begin() const noexcept
+    {
+        return ZippingIterator(first.begin(), second.begin());
+    }
+
+    auto end() const noexcept
+    {
+        return ZippingIterator(first.end(), second.end());
+    }
+};
+
+template<typename TFirst, typename TSecond>
+ZippingRange<TFirst, TSecond> zip(TFirst&& first, TSecond&& second)
+{
+    return {.first = {std::forward<TFirst>(first)}, .second = {std::forward<TSecond>(second)}};
+}
+
 template<typename TIterator>
 struct ReplacingIterator
 {