Core/Utils: restored advstd changes that went missing in last revert

Author: Ovahlord

src/common/Utilities/advstd.h

@@ -18,9 +18,91 @@
 #ifndef TRINITY_ADVSTD_H
 #define TRINITY_ADVSTD_H
 
+#include <version>
+
+#ifdef __cpp_lib_bit_cast
+#include <bit>
+#else
+#include <cstring> // for memcpy
+#endif
+#include <compare>
+
 // this namespace holds implementations of upcoming stdlib features that our c++ version doesn't have yet
 namespace advstd
 {
+// libc++ is missing these two
+[[nodiscard]] constexpr bool is_eq(std::partial_ordering cmp) noexcept { return cmp == 0; }
+[[nodiscard]] constexpr bool is_neq(std::partial_ordering cmp) noexcept { return cmp != 0; }
+
+#ifdef __cpp_lib_bit_cast
+using std::bit_cast;
+#else
+// libstdc++ v10 is missing this
+template <typename To, typename From,
+    std::enable_if_t<std::conjunction_v<
+        std::bool_constant<sizeof(To) == sizeof(From)>,
+        std::is_trivially_copyable<To>,
+        std::is_trivially_copyable<From>>, int> = 0>
+[[nodiscard]] constexpr To bit_cast(From const& from) noexcept
+{
+    To to;
+    std::memcpy(&to, &from, sizeof(To));
+    return to;
+}
+#endif
+}
+
+// std::forward_like
+#ifdef __cpp_lib_forward_like
+#include <utility>
+namespace advstd
+{
+using std::forward_like;
+}
+#else
+namespace advstd
+{
+template <class T, class U>
+[[nodiscard]] constexpr decltype(auto) forward_like(U&& value) noexcept
+{
+    using ValueU = std::remove_reference_t<U>;
+    using ValueConstU = std::conditional_t<std::is_const_v<std::remove_reference_t<T>>, ValueU const, ValueU>;
+    return static_cast<std::conditional_t<std::is_rvalue_reference_v<T&&>, ValueConstU&&, ValueConstU&>>(value);
+}
+}
+#endif
+
+// std::ranges::contains
+#include <algorithm>
+#ifndef __cpp_lib_ranges_contains
+#include <functional> // for std::ranges::equal_to, std::identity
+#include <iterator> // for std::input_iterator, std::sentinel_for, std::projected
+#endif
+
+namespace advstd::ranges
+{
+#ifndef __cpp_lib_ranges_contains
+struct Contains
+{
+    template<std::input_iterator I, std::sentinel_for<I> S, class T, class Proj = std::identity>
+    requires std::indirect_binary_predicate<std::ranges::equal_to, std::projected<I, Proj>, T const*>
+    [[nodiscard]] inline constexpr bool operator()(I first, S last, T const& value, Proj proj = {}) const
+    {
+        return std::ranges::find(std::move(first), last, value, proj) != last;
+    }
+
+    template<std::ranges::input_range R, class T, class Proj = std::identity>
+    requires std::indirect_binary_predicate<std::ranges::equal_to, std::projected<std::ranges::iterator_t<R>, Proj>, T const*>
+    [[nodiscard]] inline constexpr bool operator()(R&& r, T const& value, Proj proj = {}) const
+    {
+        auto first = std::ranges::begin(r);
+        auto last = std::ranges::end(r);
+        return std::ranges::find(std::move(first), last, value, proj) != last;
+    }
+} inline constexpr contains;
+#else
+using std::ranges::contains;
+#endif
 }
 
 #endif