Codechange: make TimerGameCalendar Date and Year types strongly typed (#10761)

src/core/math_func.hpp

@@ -10,6 +10,7 @@
 #ifndef MATH_FUNC_HPP
 #define MATH_FUNC_HPP
 
+#include "strong_typedef_type.hpp"
 
 /**
  * Returns the absolute value of (scalar) variable.
@@ -162,7 +163,7 @@ static inline uint ClampU(const uint a, const uint min, const uint max)
  * for the return type.
  * @see Clamp(int, int, int)
  */
-template <typename To, typename From>
+template <typename To, typename From, std::enable_if_t<std::is_integral<From>::value, int> = 0>
 constexpr To ClampTo(From value)
 {
 	static_assert(std::numeric_limits<To>::is_integer, "Do not clamp from non-integer values");
@@ -213,6 +214,15 @@ constexpr To ClampTo(From value)
 	return static_cast<To>(std::min<BiggerType>(value, std::numeric_limits<To>::max()));
 }
 
+/**
+ * Specialization of ClampTo for #StrongType::Typedef.
+ */
+template <typename To, typename From, std::enable_if_t<std::is_base_of<StrongTypedefBase, From>::value, int> = 0>
+constexpr To ClampTo(From value)
+{
+	return ClampTo<To>(static_cast<typename From::BaseType>(value));
+}
+
 /**
  * Returns the (absolute) difference between two (scalar) variables
  *
@@ -254,10 +264,14 @@ static inline bool IsInsideBS(const T x, const size_t base, const size_t size)
  * @param max The maximum of the interval
  * @see IsInsideBS()
  */
-template <typename T>
+template <typename T, std::enable_if_t<std::disjunction_v<std::is_convertible<T, size_t>, std::is_base_of<StrongTypedefBase, T>>, int> = 0>
 static constexpr inline bool IsInsideMM(const T x, const size_t min, const size_t max) noexcept
 {
-	return (size_t)(x - min) < (max - min);
+	if constexpr (std::is_base_of_v<StrongTypedefBase, T>) {
+		return (size_t)(static_cast<typename T::BaseType>(x) - min) < (max - min);
+	} else {
+		return (size_t)(x - min) < (max - min);
+	}
 }
 
 /**