llvm/unittests/ADT/TypeSwitchTest.cpp

   1 //===- TypeSwitchTest.cpp - TypeSwitch 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/TypeSwitch.h"
  10 #include "gtest/gtest.h"
  11
  12 using namespace llvm;
  13
  14 namespace {
  15 /// Utility classes to setup casting functionality.
  16 struct Base {
  17   enum Kind { DerivedA, DerivedB, DerivedC, DerivedD, DerivedE };
  18   Kind kind;
  19 };
  20 template <Base::Kind DerivedKind> struct DerivedImpl : Base {
  21   DerivedImpl() : Base{DerivedKind} {}
  22   static bool classof(const Base *base) { return base->kind == DerivedKind; }
  23 };
  24 struct DerivedA : public DerivedImpl<Base::DerivedA> {};
  25 struct DerivedB : public DerivedImpl<Base::DerivedB> {};
  26 struct DerivedC : public DerivedImpl<Base::DerivedC> {};
  27 struct DerivedD : public DerivedImpl<Base::DerivedD> {};
  28 struct DerivedE : public DerivedImpl<Base::DerivedE> {};
  29 } // end anonymous namespace
  30
  31 TEST(TypeSwitchTest, CaseResult) {
  32   auto translate = [](auto value) {
  33     return TypeSwitch<Base *, int>(&value)
  34         .Case<DerivedA>([](DerivedA *) { return 0; })
  35         .Case([](DerivedB *) { return 1; })
  36         .Case([](DerivedC *) { return 2; })
  37         .Default([](Base *) { return -1; });
  38   };
  39   EXPECT_EQ(0, translate(DerivedA()));
  40   EXPECT_EQ(1, translate(DerivedB()));
  41   EXPECT_EQ(2, translate(DerivedC()));
  42   EXPECT_EQ(-1, translate(DerivedD()));
  43 }
  44
  45 TEST(TypeSwitchTest, CasesResult) {
  46   auto translate = [](auto value) {
  47     return TypeSwitch<Base *, int>(&value)
  48         .Case<DerivedA, DerivedB, DerivedD>([](auto *) { return 0; })
  49         .Case([](DerivedC *) { return 1; })
  50         .Default(-1);
  51   };
  52   EXPECT_EQ(0, translate(DerivedA()));
  53   EXPECT_EQ(0, translate(DerivedB()));
  54   EXPECT_EQ(1, translate(DerivedC()));
  55   EXPECT_EQ(0, translate(DerivedD()));
  56   EXPECT_EQ(-1, translate(DerivedE()));
  57 }
  58
  59 TEST(TypeSwitchTest, CaseVoid) {
  60   auto translate = [](auto value) {
  61     int result = -2;
  62     TypeSwitch<Base *>(&value)
  63         .Case([&](DerivedA *) { result = 0; })
  64         .Case([&](DerivedB *) { result = 1; })
  65         .Case([&](DerivedC *) { result = 2; })
  66         .Default([&](Base *) { result = -1; });
  67     return result;
  68   };
  69   EXPECT_EQ(0, translate(DerivedA()));
  70   EXPECT_EQ(1, translate(DerivedB()));
  71   EXPECT_EQ(2, translate(DerivedC()));
  72   EXPECT_EQ(-1, translate(DerivedD()));
  73 }
  74
  75 TEST(TypeSwitchTest, CasesVoid) {
  76   auto translate = [](auto value) {
  77     int result = -1;
  78     TypeSwitch<Base *>(&value)
  79         .Case<DerivedA, DerivedB, DerivedD>([&](auto *) { result = 0; })
  80         .Case([&](DerivedC *) { result = 1; });
  81     return result;
  82   };
  83   EXPECT_EQ(0, translate(DerivedA()));
  84   EXPECT_EQ(0, translate(DerivedB()));
  85   EXPECT_EQ(1, translate(DerivedC()));
  86   EXPECT_EQ(0, translate(DerivedD()));
  87   EXPECT_EQ(-1, translate(DerivedE()));
  88 }
  89
  90 TEST(TypeSwitchTest, CaseOptional) {
  91   auto translate = [](auto value) {
  92     return TypeSwitch<Base *, std::optional<int>>(&value)
  93         .Case([](DerivedA *) { return 0; })
  94         .Case([](DerivedC *) { return std::nullopt; })
  95         .Default([](Base *) { return -1; });
  96   };
  97   EXPECT_EQ(0, translate(DerivedA()));
  98   EXPECT_EQ(std::nullopt, translate(DerivedC()));
  99   EXPECT_EQ(-1, translate(DerivedD()));
 100   EXPECT_EQ(std::nullopt,
 101             (TypeSwitch<Base *, std::optional<int>>(nullptr).Default(
 102                 [](Base *) { return std::nullopt; })));
 103 }
 104
 105 TEST(TypeSwitchTest, CasesOptional) {
 106   auto translate = [](auto value) {
 107     return TypeSwitch<Base *, std::optional<int>>(&value)
 108         .Case<DerivedB, DerivedC>([](auto *) { return std::nullopt; })
 109         .Case([](DerivedA *) { return 0; })
 110         .Default([](Base *) { return -1; });
 111   };
 112   EXPECT_EQ(0, translate(DerivedA()));
 113   EXPECT_EQ(std::nullopt, translate(DerivedB()));
 114   EXPECT_EQ(std::nullopt, translate(DerivedC()));
 115   EXPECT_EQ(-1, translate(DerivedD()));
 116 }