[clang-tools-extra] [clang-tidy] Add performance-inefficient-container-assignment check (PR #222159)

[Daniil Dudkin via cfe-commits]

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@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_INEFFICIENTCONTAINERASSIGNMENTCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_INEFFICIENTCONTAINERASSIGNMENTCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include <vector>
+
+namespace clang::tidy::performance {
+
+/// Finds assignments of a freshly constructed temporary container to a
+/// container of the same type and suggests the `assign` member function, or
+/// an equivalent in-place rewrite, that reuses the existing storage.
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unterumarmung wrote:

This is too verbose

https://github.com/llvm/llvm-project/pull/222159