Tests simplified and names corrected (POD->scalar)

Issue 2527
This commit is contained in:
Piotr Nycz 2019-10-24 10:22:09 +02:00
parent 37590da6c0
commit d072682119

View File

@ -651,65 +651,34 @@ template <typename T, typename = decltype(ReturnRef(std::declval<T&&>()))>
bool CanCallReturnRef(T&&) { return true; }
bool CanCallReturnRef(Unused) { return false; }
// Defined here, because gmock has to work with C++11 (std::void_t is from C++17)
template<typename... Ts> struct precpp17_make_void { typedef void type;};
template<typename... Ts> using precpp17_void_t = typename precpp17_make_void<Ts...>::type;
template <typename T, typename = void>
struct HasReturnRefAction : std::false_type {};
template <typename T>
struct HasReturnRefAction<T, precpp17_void_t<decltype(ReturnRef(std::declval<T>()))>>
: std::true_type {};
// Just an example of non-POD type
class MyNonPodType {
public:
MyNonPodType(int a_value) : value_(a_value) {}
private:
int value_;
};
// Just an example of POD type
using MyPodType = int;
// Tests that ReturnRef(v) is working with non-temporaries (T&)
TEST(ReturnRefTest, IsAcceptingNonTemporary) {
EXPECT_TRUE(HasReturnRefAction<MyPodType&>::value);
EXPECT_TRUE(HasReturnRefAction<const MyPodType&>::value);
EXPECT_TRUE(HasReturnRefAction<MyNonPodType&>::value);
EXPECT_TRUE(HasReturnRefAction<const MyNonPodType&>::value);
TEST(ReturnRefTest, WorksForNonTemporary) {
int scalarValue = 123;
EXPECT_TRUE(CanCallReturnRef(scalarValue));
MyNonPodType nonPodValue{123};
EXPECT_TRUE(CanCallReturnRef(nonPodValue));
std::string nonScalarValue("ABC");
EXPECT_TRUE(CanCallReturnRef(nonScalarValue));
MyPodType podValue{321};
EXPECT_TRUE(CanCallReturnRef(podValue));
const int constScalarValue{321};
EXPECT_TRUE(CanCallReturnRef(constScalarValue));
const MyNonPodType constNonPodValue{123};
EXPECT_TRUE(CanCallReturnRef(constNonPodValue));
const MyPodType constPodValue{321};
EXPECT_TRUE(CanCallReturnRef(constPodValue));
const std::string constNonScalarValue("CBA");
EXPECT_TRUE(CanCallReturnRef(constNonScalarValue));
}
// Tests that ReturnRef(v) is not working with temporaries (T&&)
TEST(ReturnRefTest, IsNotAcceptingTemporary) {
EXPECT_FALSE(HasReturnRefAction<MyPodType&&>::value);
EXPECT_FALSE(HasReturnRefAction<const MyPodType&&>::value);
EXPECT_FALSE(HasReturnRefAction<MyNonPodType&&>::value);
EXPECT_FALSE(HasReturnRefAction<const MyNonPodType&&>::value);
TEST(ReturnRefTest, DoesNotWorkForTemporary) {
auto scalarValue = []() -> int { return 123; };
EXPECT_FALSE(CanCallReturnRef(scalarValue()));
auto nonPodValue = []() -> MyNonPodType { return MyNonPodType{123}; };
EXPECT_FALSE(CanCallReturnRef(nonPodValue()));
auto nonScalarValue = []() -> std::string { return "ABC"; };
EXPECT_FALSE(CanCallReturnRef(nonScalarValue()));
auto podValue = []() -> MyPodType { return MyPodType{321}; };
EXPECT_FALSE(CanCallReturnRef(podValue()));
// cannot use here callable returning "const scalar type" because C++ ignores such const for scalar return type, so the static_cast
EXPECT_FALSE(CanCallReturnRef(static_cast<const int>(321)));
auto constNonPodValue = []() -> const MyNonPodType { return MyNonPodType{123}; };
EXPECT_FALSE(CanCallReturnRef(constNonPodValue()));
// cannot use here callable returning "const POD" because C++ ignores such const for POD return type, so the static_cast
EXPECT_FALSE(CanCallReturnRef(static_cast<const MyPodType>(42)));
auto constNonScalarValue = []() -> const std::string { return "CBA"; };
EXPECT_FALSE(CanCallReturnRef(constNonScalarValue()));
}
// Tests that ReturnRefOfCopy(v) works for reference types.