当您在中定义常量时enum class MyEnum
你将它们定义为对象用户定义类型 MyEnum
没有隐式转换
到任何整数类型。那就是goal of enum class
这不是
让 Googletest 假设您想要类型的对象MyEnum
自动地
转换为整数类型以便插入到输出
流,如果您选择将该类型设为enum class
不仅仅是
一个enum
.
所以你观察到的不是 Googletest 错误。这只是 Googletest 使用它的
某种类型的用户定义对象的后备表示T
为此
std::ostream & operator<<(std::ostream &, T const &);
未定义。
如果你想查看类型对象的整数值enum class MyEnum
对于出现在Googletest的诊断中的测试,您至少有两种方法。
一种方法是简单地将测试应用于基础积分值的物体,
如:
主要.cpp (1)
#include <gtest/gtest.h>
#include <type_traits>
enum class MyEnum {
Value,
Value2
};
auto as_integral(MyEnum me)
-> std::underlying_type<MyEnum>::type
{
return static_cast<std::underlying_type<MyEnum>::type>(me);
}
TEST(foo,bar)
{
EXPECT_EQ(as_integral(MyEnum::Value),as_integral(MyEnum::Value2));
}
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
编译、链接并运行:
$ g++ -std=c++11 -Wall -Wextra -o gtester main.cpp -lgtest -lpthread
$ ./gtester
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from foo
[ RUN ] foo.bar
main.cpp:17: Failure
Expected equality of these values:
as_integral(MyEnum::Value)
Which is: 0
as_integral(MyEnum::Value2)
Which is: 1
[ FAILED ] foo.bar (0 ms)
[----------] 1 test from foo (1 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (1 ms total)
[ PASSED ] 0 tests.
[ FAILED ] 1 test, listed below:
[ FAILED ] foo.bar
1 FAILED TEST
另一种更好的方法是向 Googletest 提供以下定义:
std::ostream & operator<<(std::ostream &, MyEnum const &);
这适合你。然后 Googletest 将在诊断中使用它,如下所示:
主.cpp (2)
#include <gtest/gtest.h>
#include <type_traits>
#include <ostream>
enum class MyEnum {
Value,
Value2
};
auto as_integral(MyEnum me)
-> std::underlying_type<MyEnum>::type
{
return static_cast<std::underlying_type<MyEnum>::type>(me);
}
std::ostream & operator<<(std::ostream & out, MyEnum me)
{
return out << as_integral(me);
}
TEST(foo,bar)
{
EXPECT_EQ(MyEnum::Value,MyEnum::Value2);
}
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
编译、链接并运行:
$ g++ -std=c++11 -Wall -Wextra -o gtester main.cpp -lgtest -lpthread
$ ./gtester
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from foo
[ RUN ] foo.bar
main.cpp:23: Failure
Expected equality of these values:
MyEnum::Value
Which is: 0
MyEnum::Value2
Which is: 1
[ FAILED ] foo.bar (0 ms)
[----------] 1 test from foo (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (0 ms total)
[ PASSED ] 0 tests.
[ FAILED ] 1 test, listed below:
[ FAILED ] foo.bar
1 FAILED TEST