From e9e2e3107d6b4fb1bfdd877a83f1e214fcefea76 Mon Sep 17 00:00:00 2001
From: Sean Silva <silvasean@google.com>
Date: Thu, 5 Nov 2020 16:00:38 -0800
Subject: [PATCH] [STLExtras] Add append_range helper.

This is convenient in a lot of cases, such as when the thing you want
to append is `someReallyLongFunctionName()` that you'd rather not
write twice or assign to a variable for the paired begin/end calls.

Differential Revision: https://reviews.llvm.org/D90894
---
 llvm/include/llvm/ADT/STLExtras.h    | 8 ++++++++
 llvm/unittests/ADT/STLExtrasTest.cpp | 9 +++++++++
 2 files changed, 17 insertions(+)

diff --git a/llvm/include/llvm/ADT/STLExtras.h b/llvm/include/llvm/ADT/STLExtras.h
index f3f9f20..5a5d47b 100644
--- a/llvm/include/llvm/ADT/STLExtras.h
+++ b/llvm/include/llvm/ADT/STLExtras.h
@@ -1676,6 +1676,14 @@ void erase_value(Container &C, ValueType V) {
   C.erase(std::remove(C.begin(), C.end(), V), C.end());
 }
 
+/// Wrapper function to append a range to a container.
+///
+/// C.insert(C.end(), R.begin(), R.end());
+template <typename Container, typename Range>
+inline void append_range(Container &C, Range &&R) {
+  C.insert(C.end(), R.begin(), R.end());
+}
+
 /// Given a sequence container Cont, replace the range [ContIt, ContEnd) with
 /// the range [ValIt, ValEnd) (which is not from the same container).
 template<typename Container, typename RandomAccessIterator>
diff --git a/llvm/unittests/ADT/STLExtrasTest.cpp b/llvm/unittests/ADT/STLExtrasTest.cpp
index aaef46a..a4e151c 100644
--- a/llvm/unittests/ADT/STLExtrasTest.cpp
+++ b/llvm/unittests/ADT/STLExtrasTest.cpp
@@ -323,6 +323,15 @@ TEST(STLExtrasTest, EraseIf) {
   EXPECT_EQ(7, V[3]);
 }
 
+TEST(STLExtrasTest, AppendRange) {
+  auto AppendVals = {3};
+  std::vector<int> V = {1, 2};
+  append_range(V, AppendVals);
+  EXPECT_EQ(1, V[0]);
+  EXPECT_EQ(2, V[1]);
+  EXPECT_EQ(3, V[2]);
+}
+
 namespace some_namespace {
 struct some_struct {
   std::vector<int> data;
-- 
2.7.4