1 files changed, 92 insertions, 0 deletions
diff --git a/serialize/packbits-read.hpp b/serialize/packbits-read.hpp
new file mode 100644
index 00000000..32eca8df
--- /dev/null
+++ b/serialize/packbits-read.hpp
@@ -0,0 +1,92 @@
+#pragma once
+#include "packbits.hpp"
+#include <type_traits>
+#include <concepts>
+#include <tuple>
+#include "compat/assert.hpp"
+
+namespace floormat::detail_Pack {
+
+template<std::unsigned_integral T, size_t CAPACITY>
+struct input
+{
+    static_assert(CAPACITY <= sizeof(T)*8);
+
+    using Type = T;
+    static constexpr size_t Capacity = CAPACITY;
+    T value;
+
+    template<size_t N>
+    constexpr T get() const
+    {
+        static_assert(N > 0);
+        static_assert(N <= sizeof(T)*8);
+        static_assert(N <= Capacity);
+        return T(value & (T(1) << N) - T(1));
+    }
+
+    template<size_t N>
+    constexpr T advance() const
+    {
+        static_assert(N <= sizeof(T)*8);
+        static_assert(N <= Capacity);
+        return T(value >> N);
+    }
+
+    constexpr bool operator==(const input&) const noexcept = default;
+    [[nodiscard]] constexpr inline bool check_zero() const { return value == T(0); }
+
+    template<size_t N> using next = input<T, Capacity - N>;
+};
+
+template<std::unsigned_integral T>
+struct input<T, 0>
+{
+    using Type = T;
+    static constexpr size_t Capacity = 0;
+    T value;
+
+    template<size_t N> [[maybe_unused]] constexpr T get() const = delete;
+    template<size_t N> [[maybe_unused]] constexpr T advance() const = delete;
+    constexpr bool operator==(const input&) const noexcept = default;
+    [[nodiscard]] constexpr inline bool check_zero() const { return true; }
+
+    template<size_t N> struct next
+    {
+        static_assert(N == 0, "reading past the end");
+        static_assert(N != 0, "reading past the end");
+    };
+};
+
+template<std::unsigned_integral T, typename Place, size_t Left, size_t I, size_t... Is, size_t Size, typename... Sizes>
+constexpr void read(Place& p, input<T, Left> st, std::index_sequence<I, Is...>, empty_pack_tuple<bits<T, Size>, Sizes...>)
+{
+    static_assert(sizeof...(Is) == sizeof...(Sizes));
+    static_assert(Size <= Left, "too many bits requested");
+    static_assert(I < std::tuple_size_v<Place>, "too few tuple members");
+    using S = input<T, Left>;
+    using next_type = typename S::template next<Size>;
+    get<I>(p) = st.template get<Size>();
+    T next_value = st.template advance<Size>();
+    read(p, next_type{ next_value }, std::index_sequence<Is...>{}, empty_pack_tuple<Sizes...>{});
+}
+
+template<std::unsigned_integral T, typename Place, size_t Left>
+constexpr void read(Place&, input<T, Left> st, std::index_sequence<>, empty_pack_tuple<>)
+{
+    fm_assert(st.check_zero());
+}
+
+template<std::unsigned_integral T, typename Place, size_t Left, size_t... Is, typename... Sizes>
+requires(sizeof...(Is) != sizeof...(Sizes))
+constexpr void read(Place&, input<T, Left>, std::index_sequence<Is...>, empty_pack_tuple<Sizes...>) = delete;
+
+template<std::unsigned_integral T, size_t... Ns> using make_pack = empty_pack_tuple<bits<T, Ns>...>;
+
+} // namespace floormat::detail_Pack
+
+namespace floormat::Pack {
+
+
+
+} // namespace floormat::Pack