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