🏷️ Add 'PickRandomlyAmong' function that picks one value from a set of values randomly

This will be used in a few places where we previously used a raw integer random to index into a local array for selection, simplifying that type of logic to a single statement.

Source/engine/random.hpp

@@ -7,7 +7,9 @@
  */
 #pragma once
 
+#include <algorithm>
 #include <cstdint>
+#include <initializer_list>
 
 namespace devilution {
 
@@ -57,4 +59,18 @@ int32_t AdvanceRndSeed();
  */
 int32_t GenerateRnd(int32_t v);
 
+/**
+ * @brief Picks one of the elements in the list randomly.
+ *
+ * @param values The values to pick from
+ * @return A random value from the 'values' list.
+ */
+template <typename T>
+const T PickRandomlyAmong(const std::initializer_list<T> &values)
+{
+	const auto index { std::max<int32_t>(GenerateRnd(values.size()), 0) };
+
+	return *(values.begin() + index);
+}
+
 } // namespace devilution

Source/objects.cpp

@@ -3966,26 +3966,11 @@ bool OperateFountains(int pnum, int i)
 
 void OperateWeaponRack(int pnum, int i, bool sendmsg)
 {
-	ItemType weaponType { ItemType::ITYPE_NONE };
-
 	if (Objects[i]._oSelFlag == 0)
 		return;
 	SetRndSeed(Objects[i]._oRndSeed);
 
-	switch (GenerateRnd(4) + ITYPE_SWORD) {
+	ItemType weaponType { PickRandomlyAmong({ ITYPE_SWORD, ITYPE_AXE, ITYPE_BOW, ITYPE_MACE }) };
-	case ITYPE_SWORD:
-		weaponType = ITYPE_SWORD;
-		break;
-	case ITYPE_AXE:
-		weaponType = ITYPE_AXE;
-		break;
-	case ITYPE_BOW:
-		weaponType = ITYPE_BOW;
-		break;
-	case ITYPE_MACE:
-		weaponType = ITYPE_MACE;
-		break;
-	}
 
 	Objects[i]._oSelFlag = 0;
 	Objects[i]._oAnimFrame++;