unittests/ADT/FunctionRefTest.cpp

   1 //===- llvm/unittest/ADT/MakeUniqueTest.cpp - std::make_unique unit tests ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/STLExtras.h"
  10 #include "gtest/gtest.h"
  11
  12 using namespace llvm;
  13
  14 namespace {
  15
  16 // Ensure that there is a default constructor and we can test for a null
  17 // function_ref.
  18 TEST(FunctionRefTest, Null) {
  19   function_ref<int()> F;
  20   EXPECT_FALSE(F);
  21
  22   auto L = [] { return 1; };
  23   F = L;
  24   EXPECT_TRUE(F);
  25
  26   F = {};
  27   EXPECT_FALSE(F);
  28 }
  29
  30 // Ensure that copies of a function_ref copy the underlying state rather than
  31 // causing one function_ref to chain to the next.
  32 TEST(FunctionRefTest, Copy) {
  33   auto A = [] { return 1; };
  34   auto B = [] { return 2; };
  35   function_ref<int()> X = A;
  36   function_ref<int()> Y = X;
  37   X = B;
  38   EXPECT_EQ(1, Y());
  39 }
  40
  41 }