Added the Abseil library which is now a dependency of RE2

3rd_Party/README.md

@@ -33,6 +33,7 @@ Verify the Xcode version with `xcode-select -p`.
 
 | Library         | Version    | Released   | Source Code
 | --------------- | ---------- | ---------- | -----------------------------------------
+| abseil          | 2024.07.22 | 2024.08.01 | https://github.com/abseil/abseil-cpp.git
 | appauth         | 1.7.5      | 2024.04.23 | https://github.com/openid/AppAuth-iOS.git
 | boost           | 1.85.0     | 2024.04.15 | https://boostorg.jfrog.io/artifactory/main/release/1.85.0/source/boost_1_85_0.tar.gz
 | bz2             | 1.0.8      | 2019.07.13 | https://sourceware.org/git/bzip2.git

3rd_Party/abseil/bootstrap.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+set -o pipefail
+set -o xtrace
+set -e
+
+CUR_DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )
+TMP_DIR=${CUR_DIR}/abseil.tmp
+
+mkdir ${TMP_DIR}
+cd ${TMP_DIR}
+
+git clone -b 20240722.0 --single-branch --depth=1 https://github.com/abseil/abseil-cpp.git
+cd abseil-cpp
+mkdir build_cmake
+cd build_cmake
+cmake \
+  -D CMAKE_BUILD_TYPE=Release\
+  -D CMAKE_OSX_ARCHITECTURES="arm64;x86_64" \
+  -D CMAKE_OSX_DEPLOYMENT_TARGET="10.15" \
+  -D CMAKE_CXX_FLAGS="-fvisibility=hidden -flto -Os" \
+  -D CMAKE_CXX_STANDARD="23" \
+  -D CMAKE_INSTALL_PREFIX="${TMP_DIR}" \
+  -D BUILD_SHARED_LIBS=OFF \
+  -D BUILD_TESTING=OFF\
+  ..
+cmake --build . --target install -j
+
+cd ../../..
+
+rm -rf ./include/
+rm -rf ./lib/
+cp -r ./abseil.tmp/include .
+cp -r ./abseil.tmp/lib .
+rm -rf ./lib/pkgconfig
+
+rm -rf ${TMP_DIR}

3rd_Party/abseil/include/absl/algorithm/algorithm.h

@@ -0,0 +1,64 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// -----------------------------------------------------------------------------
+// File: algorithm.h
+// -----------------------------------------------------------------------------
+//
+// This header file contains Google extensions to the standard <algorithm> C++
+// header.
+
+#ifndef ABSL_ALGORITHM_ALGORITHM_H_
+#define ABSL_ALGORITHM_ALGORITHM_H_
+
+#include <algorithm>
+#include <iterator>
+#include <type_traits>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+
+// equal()
+// rotate()
+//
+// Historical note: Abseil once provided implementations of these algorithms
+// prior to their adoption in C++14. New code should prefer to use the std
+// variants.
+//
+// See the documentation for the STL <algorithm> header for more information:
+// https://en.cppreference.com/w/cpp/header/algorithm
+using std::equal;
+using std::rotate;
+
+// linear_search()
+//
+// Performs a linear search for `value` using the iterator `first` up to
+// but not including `last`, returning true if [`first`, `last`) contains an
+// element equal to `value`.
+//
+// A linear search is of O(n) complexity which is guaranteed to make at most
+// n = (`last` - `first`) comparisons. A linear search over short containers
+// may be faster than a binary search, even when the container is sorted.
+template <typename InputIterator, typename EqualityComparable>
+bool linear_search(InputIterator first, InputIterator last,
+                   const EqualityComparable& value) {
+  return std::find(first, last, value) != last;
+}
+
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_ALGORITHM_ALGORITHM_H_