Added comparison operators to Either

This commit is contained in:
Sebastian Messmer 2015-06-25 16:27:26 +02:00
parent 2d7dc8c583
commit e1c4327338
2 changed files with 77 additions and 14 deletions

View File

@ -2,11 +2,14 @@
#ifndef MESSMER_CPP_UTILS_EITHER_H
#define MESSMER_CPP_UTILS_EITHER_H
#include <type_traits>
namespace cpputils {
template<class Left, class Right>
class Either final {
public:
//TODO Try allowing construction with any type that std::is_convertible to Left or Right.
Either(const Left &left): _side(Side::left) {
new(&_left)Left(left);
}
@ -19,6 +22,7 @@ namespace cpputils {
Either(Right &&right): _side(Side::right) {
new(&_right)Right(std::move(right));
}
//TODO Try allowing copy-construction when Left/Right types are std::is_convertible
Either(const Either<Left, Right> &rhs): _side(rhs._side) {
if(_side == Side::left) {
new(&_left)Left(rhs._left);
@ -33,19 +37,6 @@ namespace cpputils {
new(&_right)Right(std::move(rhs._right));
}
}
//TODO Test copy assignment operator
//TODO Copy assignment operator
//TODO Test destruction after copy assignment
//TODO Test move assignment operator
//TODO Move assignment operator
//TODO Test destruction after move assignment
//TODO Test operator==/operator!=
//TODO operator==/operator!=
//TODO Test operator<<
//TODO operator<<(ostream)
~Either() {
if (_side == Side::left) {
@ -55,6 +46,17 @@ namespace cpputils {
}
}
//TODO Test copy assignment operator
//TODO Copy assignment operator
//TODO Test destruction after copy assignment
//TODO Test move assignment operator
//TODO Move assignment operator
//TODO Test destruction after move assignment
//TODO Test operator<<
//TODO operator<<(ostream)
bool is_left() const {
return _side == Side::left;
}
@ -72,7 +74,6 @@ namespace cpputils {
return _right;
}
//TODO Test const and non-const left()/right()
Left &left() {
return const_cast<Left&>(const_cast<const Either<Left, Right>*>(this)->left());
}
@ -87,6 +88,23 @@ namespace cpputils {
enum class Side : unsigned char {left, right} _side;
};
template<class Left, class Right>
bool operator==(const Either<Left, Right> &lhs, const Either<Left, Right> &rhs) {
if (lhs.is_left() != rhs.is_left()) {
return false;
}
if (lhs.is_left()) {
return lhs.left() == rhs.left();
} else {
return lhs.right() == rhs.right();
}
}
template<class Left, class Right>
bool operator!=(const Either<Left, Right> &lhs, const Either<Left, Right> &rhs) {
return !operator==(lhs, rhs);
}
//TODO Test make_either<>
//TODO make_either<>
}

View File

@ -142,6 +142,51 @@ TEST_F(EitherTest, RightCanBeMoved) {
EXPECT_EQ(5, val2.right().value);
}
TEST_F(EitherTest, LeftEquals) {
Either<string, int> val1 = string("mystring");
Either<string, int> val2 = string("mystring");
EXPECT_TRUE(val1 == val2);
EXPECT_TRUE(val2 == val1);
EXPECT_FALSE(val1 != val2);
EXPECT_FALSE(val2 != val1);
}
TEST_F(EitherTest, LeftNotEquals) {
Either<string, int> val1 = string("mystring");
Either<string, int> val2 = string("mystring2");
EXPECT_TRUE(val1 != val2);
EXPECT_TRUE(val2 != val1);
EXPECT_FALSE(val1 == val2);
EXPECT_FALSE(val2 == val1);
}
TEST_F(EitherTest, RightEquals) {
Either<int, string> val1 = string("mystring");
Either<int, string> val2 = string("mystring");
EXPECT_TRUE(val1 == val2);
EXPECT_TRUE(val2 == val1);
EXPECT_FALSE(val1 != val2);
EXPECT_FALSE(val2 != val1);
}
TEST_F(EitherTest, RightNotEquals) {
Either<int, string> val1 = string("mystring");
Either<int, string> val2 = string("mystring2");
EXPECT_TRUE(val1 != val2);
EXPECT_TRUE(val2 != val1);
EXPECT_FALSE(val1 == val2);
EXPECT_FALSE(val2 == val1);
}
TEST_F(EitherTest, LeftNotEqualsRight) {
Either<string, int> val1 = string("mystring");
Either<string, int> val2 = 3;
EXPECT_TRUE(val1 != val2);
EXPECT_TRUE(val2 != val1);
EXPECT_FALSE(val1 == val2);
EXPECT_FALSE(val2 == val1);
}
class DestructorCallback {
public:
MOCK_CONST_METHOD0(call, void());