回答編集履歴
1
getを工夫
answer
CHANGED
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@@ -3,6 +3,7 @@
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3
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```
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#include <iostream>
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#include <cstdint>
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6
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+
#include <type_traits>
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class Direction {
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public:
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using value_type = std::uint8_t;
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@@ -30,18 +31,21 @@
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constexpr void reverse() noexcept {
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this->value = (this->value + 2) & 0b11;
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}
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+
template<typename T = value_type, std::enable_if_t<std::is_arithmetic<T>::value, std::nullptr_t> = nullptr>
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-
constexpr
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35
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constexpr T get() const noexcept {
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return this->value;
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}
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};
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int main() {
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Direction a(Direction::front);
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-
std::cout << a.get() << std::endl;
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std::cout << a.get<unsigned>() << std::endl;
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-
a.
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a.turn_left();
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-
std::cout << a.get() << std::endl;
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std::cout << a.get<unsigned>() << std::endl;
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return 0;
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}
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```
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49
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+
こんなのかな。
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50
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+
[動作](http://melpon.org/wandbox/permlink/MlttJTjNsdm9lv94)
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47
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-
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51
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+
sprout使えばコンパイル時に文字列使えるけどそこまでしたくない
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