[llvm] [llvm][ADT] Add wrappers to `std::includes` (PR #143297)

[Jakub Kuderski via llvm-commits]

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@@ -1567,6 +1567,30 @@ TEST(STLExtrasTest, Mismatch) {
   }
 }
 
+TEST(STLExtrasTest, Includes) {
+  {
+    std::vector<int> V1 = {1, 2};
+    std::vector<int> V2;
+    EXPECT_TRUE(includes(V1, V2));
+    EXPECT_FALSE(includes(V2, V1));
+    V2.push_back(1);
+    EXPECT_TRUE(includes(V1, V2));
+    V2.push_back(3);
+    EXPECT_FALSE(includes(V1, V2));
+  }
+
+  {
+    std::vector<int> V1 = {3, 2, 1};
+    std::vector<int> V2;
+    EXPECT_TRUE(includes(V1, V2, deref<std::greater<>>()));
+    EXPECT_FALSE(includes(V2, V1, deref<std::greater<>>()));
+    V2.push_back(3);
+    EXPECT_TRUE(includes(V1, V2, deref<std::greater<>>()));
+    V2.push_back(0);
+    EXPECT_FALSE(includes(V1, V2, deref<std::greater<>>()));
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kuhar wrote:

Why do we need the `deref`?

https://github.com/llvm/llvm-project/pull/143297