Codechange: Give StrongType an implicit/explict constructor template …

…parameter.

This allows a StrongType to be even stronger as implicit conversions are prevented.

src/core/strong_typedef_type.hpp

@@ -148,17 +148,18 @@ namespace StrongType {
 	 *
 	 * @tparam TBaseType Type of the derived class (i.e. the concrete usage of this class).
 	 * @tparam TTag An unique struct to keep types of the same TBaseType distinct.
+	 * @tparam TExplicitConstructor Enable explicit constructor instead of implicit constructor.
 	 * @tparam TProperties A list of mixins to add to the class.
 	 */
-	template <typename TBaseType, typename TTag, typename... TProperties>
-	struct EMPTY_BASES Typedef : public StrongTypedefBase, public TProperties::template mixin<Typedef<TBaseType, TTag, TProperties...>, TBaseType>... {
+	template <typename TBaseType, typename TTag, bool TExplicitConstructor, typename... TProperties>
+	struct EMPTY_BASES Typedef : public StrongTypedefBase, public TProperties::template mixin<Typedef<TBaseType, TTag, TExplicitConstructor, TProperties...>, TBaseType>... {
 		using BaseType = TBaseType;
 
 		constexpr Typedef() = default;
 		constexpr Typedef(const Typedef &) = default;
 		constexpr Typedef(Typedef &&) = default;
 
-		constexpr Typedef(const TBaseType &value) : value(value) {}
+		constexpr explicit(TExplicitConstructor) Typedef(const TBaseType &value) : value(value) {}
 
 		constexpr Typedef &operator =(const Typedef &rhs) { this->value = rhs.value; return *this; }
 		constexpr Typedef &operator =(Typedef &&rhs) { this->value = std::move(rhs.value); return *this; }

src/tile_type.h

@@ -84,7 +84,7 @@ enum TropicZone {
  *
  * It is compatible with int32 / int64 for easy math throughout the code.
  */
-using TileIndex = StrongType::Typedef<uint32_t, struct TileIndexTag, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer, StrongType::Compatible<int32_t>, StrongType::Compatible<int64_t>>;
+using TileIndex = StrongType::Typedef<uint32_t, struct TileIndexTag, false, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer, StrongType::Compatible<int32_t>, StrongType::Compatible<int64_t>>;
 
 /* Make sure the size is as expected. */
 static_assert(sizeof(TileIndex) == 4);

src/timer/timer_game_common.h

@@ -32,14 +32,14 @@ class TimerGame {
 public:
 	/** The type to store our dates in. */
 	template <class ST> struct DateTag;
-	using Date = StrongType::Typedef<int32_t, DateTag<T>, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer>;
+	using Date = StrongType::Typedef<int32_t, DateTag<T>, false, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer>;
 
 	/** The fraction of a date we're in, i.e. the number of ticks since the last date changeover. */
 	using DateFract = uint16_t;
 
 	/** Type for the year, note: 0 based, i.e. starts at the year 0. */
 	template <class ST> struct YearTag;
-	using Year = StrongType::Typedef<int32_t, struct YearTag<T>, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer>;
+	using Year = StrongType::Typedef<int32_t, struct YearTag<T>, false, StrongType::CompareSelf, StrongType::CompareBase, StrongType::Integer>;
 	/** Type for the month, note: 0 based, i.e. 0 = January, 11 = December. */
 	using Month = uint8_t;
 	/** Type for the day of the month, note: 1 based, first day of a month is 1. */