1 files changed, 62 insertions, 0 deletions
diff --git a/src/qdoc/catch_generators/src/catch_generators/utilities/semantics/move_into_vector.h b/src/qdoc/catch_generators/src/catch_generators/utilities/semantics/move_into_vector.h
new file mode 100644
index 000000000..5e780085b
--- /dev/null
+++ b/src/qdoc/catch_generators/src/catch_generators/utilities/semantics/move_into_vector.h
@@ -0,0 +1,62 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include "../../namespaces.h"
+
+#include <vector>
+#include <tuple>
+
+namespace QDOC_CATCH_GENERATORS_UTILITIES_ABSOLUTE_NAMESPACE {
+
+    namespace QDOC_CATCH_GENERATORS_TRAITS_NAMESPACE {
+
+        /*!
+         * Returns the type of the first element of Args.
+         *
+         * Args is expected to have at least one
+         */
+        template<typename... Args>
+        using first_from_pack_t = std::tuple_element_t<0, std::tuple<Args...>>;
+
+    } // end QDOC_CATCH_GENERATORS_TRAITS_NAMESPACE
+
+
+    /*!
+     * Builds an std::vector by moving \a movables into it.
+     *
+     * \a movables must be made of homogenous types.
+     *
+     * This function is intended to allow the construction of an
+     * std::vector<T>, where T is a move only type, as an expression,
+     * to lighten the idiom.
+     *
+     * For example, Catch's GeneratorWrapper<T> adapts a
+     * std::unique_ptr, which is move only, making it impossible to
+     * build a std::vector from them in place.
+     *
+     * Then, everywhere this is needed, a more complex approach of
+     * generating the collection of objects, generating a vector of a
+     * suitable size and iterating the objects to move-emplace them in
+     * the vector is required.
+     *
+     * This not only complicates the code but is incompatible with a
+     * GENERATE expression, making it extremely hard, noisy and error
+     * prone to use them together.
+     *
+     * In those cases, then, a call to move_into_vector can be used as
+     * an expression to circumvent the problem.
+     */
+    template<typename... MoveOnlyTypes>
+    inline auto move_into_vector(MoveOnlyTypes... movables) {
+        std::vector<QDOC_CATCH_GENERATORS_TRAITS_NAMESPACE::first_from_pack_t<MoveOnlyTypes...>>
+            moved_into_vector;
+        moved_into_vector.reserve(sizeof...(movables));
+
+        (moved_into_vector.emplace_back(std::move(movables)), ...);
+
+        return moved_into_vector;
+    }
+
+} // end QDOC_CATCH_GENERATORS_UTILITIES_ABSOLUTE_NAMESPACE