[clang-tools-extra] [llvm] [clang] [libcxx] [libcxx] adds ranges::fold_left_with_iter and ranges::fold_left (PR #75259)

[Christopher Di Bella via cfe-commits]

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@@ -0,0 +1,100 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 TEST_SUPPORT_INVOCABLE_WITH_TELEMETRY_H
+#define TEST_SUPPORT_INVOCABLE_WITH_TELEMETRY_H
+
+#include <cassert>
+#include <concepts>
+#include <utility>
+
+#if TEST_STD_VER < 20
+#  error invocable_with_telemetry requires C++20
+#else
+template <class F>
+class invocable_with_telemetry {
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cjdb wrote:

I've added `invocable_telemetry` to structure this a bit better.

https://github.com/llvm/llvm-project/pull/75259