QmlDesigner: Add compare factory

Instead of writing a complicated lambda a compare factory can be used to
generate them.

Instead of:

std::ranges::sort(foo, [] (const Foo &first, const Foo &second) {
    return std::tie(first.name, first.version)
         < std::tie(second.name, second.version);
});

you can write:

std::ranges::sort(foos, makeLess(&Foo::name, &Foo::version));

Change-Id: I4daa5639f007a006a152d7b17688c189b3249cd8
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/libs/designercore/CMakeLists.txt

@@ -30,6 +30,7 @@ extend_qtc_library(QmlDesignerCore
   PUBLIC_INCLUDES designercoreutils
   SOURCES_PREFIX designercoreutils
   SOURCES
+    functional.h
     generatedcomponentutils.cpp
     generatedcomponentutils.h
     modelmerger.cpp

src/plugins/qmldesigner/libs/designercore/designercoreutils/functional.h

@@ -0,0 +1,32 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include <functional>
+#include <tuple>
+
+namespace QmlDesigner {
+
+inline constexpr auto makeCompare = [](auto... projections) {
+    return [=](auto compare) {
+        return [=](const auto &first, const auto &second) {
+            return compare(std::forward_as_tuple(std::invoke(projections, first)...),
+                           std::forward_as_tuple(std::invoke(projections, second)...));
+        };
+    };
+};
+
+inline constexpr auto makeLess = [](auto... projections) {
+    return [=](const auto &first, const auto &second) {
+        return std::ranges::less(std::forward_as_tuple(std::invoke(projections, first)...),
+                                 std::forward_as_tuple(std::invoke(projections, second)...));
+    };
+};
+
+inline constexpr auto makeEqual = [](auto... projections) {
+    return [=](const auto &first, const auto &second) {
+        return std::ranges::equal_to(std::forward_as_tuple(std::invoke(projections, first)...),
+                                     std::forward_as_tuple(std::invoke(projections, second)...));
+    };
+};
+
+} // namespace QmlDesigner

src/plugins/qmldesigner/libs/designercore/projectstorage/projectstorageupdater.cpp

@@ -13,6 +13,7 @@
 #include "sourcepathstorage/sourcepathcache.h"
 #include "typeannotationreader.h"
 
+#include <functional.h>
 #include <sqlitedatabase.h>
 #include <tracing/qmldesignertracing.h>
 #include <utils/algorithm.h>
@@ -1173,16 +1174,7 @@ void removeDuplicates(Storage::Synchronization::ExportedTypes &exportedTypes)
 {
     using Storage::Synchronization::ExportedType;
 
-    auto factory = [](auto... projections) {
+    auto compare = makeCompare(&ExportedType::name, &ExportedType::version);
-        return [=](auto compare) {
-            return [=](const auto &first, const auto &second) {
-                return compare(std::forward_as_tuple(std::invoke(projections, first)...),
-                               std::forward_as_tuple(std::invoke(projections, second)...));
-            };
-        };
-    };
-
-    auto compare = factory(&ExportedType::name, &ExportedType::version);
     auto less = compare(std::ranges::less{});
     auto equal = compare(std::ranges::equal_to{});