util: add fourcc, intrusive list fixes

libraries/libvapours/include/vapours/util.hpp

@@ -19,6 +19,7 @@
 
 #include "util/util_alignment.hpp"
 #include "util/util_size.hpp"
+#include "util/util_fourcc.hpp"
 #include "util/util_scope_guard.hpp"
 #include "util/util_typed_storage.hpp"
 #include "util/util_intrusive_list.hpp"

libraries/libvapours/include/vapours/util/util_fourcc.hpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include "../defines.hpp"
+
+namespace ams::util {
+
+    template<char A, char B, char C, char D>
+    struct FourCC {
+        /* TODO: C++20 std::endian */
+        static constexpr u32 Code = (static_cast<u32>(A) << 0x18) |
+                                    (static_cast<u32>(B) << 0x10) |
+                                    (static_cast<u32>(C) << 0x08) |
+                                    (static_cast<u32>(D) << 0x00);
+
+        static constexpr const char String[] = {D, C, B, A};
+
+        static_assert(sizeof(Code)   == 4);
+        static_assert(sizeof(String) == 4);
+    };
+
+    template<char A, char B, char C, char D>
+    struct ReverseFourCC {
+        /* TODO: C++20 std::endian */
+        static constexpr u32 Code = (static_cast<u32>(A) << 0x00) |
+                                    (static_cast<u32>(B) << 0x08) |
+                                    (static_cast<u32>(C) << 0x10) |
+                                    (static_cast<u32>(D) << 0x18);
+
+        static constexpr const char String[] = {A, B, C, D};
+
+        static_assert(sizeof(Code)   == 4);
+        static_assert(sizeof(String) == 4);
+    };
+
+}

libraries/libvapours/include/vapours/util/util_intrusive_list.hpp

@@ -68,9 +68,9 @@ namespace ams::util {
                 /* Splice a range into the list. */
                 auto last_prev = last->prev;
                 first->prev = this;
-                this->next = first;
                 last_prev->next = next;
                 this->next->prev = last_prev;
+                this->next = first;
             }
 
             void Unlink() {
@@ -500,7 +500,7 @@ namespace ams::util {
             }
 
             void push_front(reference ref) {
-                this->impl.push_back(GetNode(ref));
+                this->impl.push_front(GetNode(ref));
             }
 
             void pop_back() {