feat(furvm): allow setting thing's value

furvm/include/furvm/thing.hpp

@@ -427,6 +427,12 @@ public:
         if (!detail::thing_traits<T>{}(*m_type)) throw bad_thing_access();
         return *std::launder(reinterpret_cast<const T*>(m_data));
     }
+
+    template <typename T>
+    void set(T&& newValue) {
+        if (!detail::thing_traits<T>{}(*m_type)) throw bad_thing_access();
+        *std::launder(reinterpret_cast<T*>(m_data)) = std::forward<T>(newValue);
+    }
 public:
     /**
      * @brief Returns a sum of two things.

furvm/test/test.cpp

@@ -84,6 +84,9 @@ TEST(ThingOps, Access) {
     EXPECT_THROW(thing.get<furvm::s8>(), furvm::bad_thing_access);
     EXPECT_THROW(thing.get<furvm::s32>(), furvm::bad_thing_access);
     EXPECT_THROW(thing.get<void*>(), furvm::bad_thing_access);
+
+    EXPECT_NO_THROW(thing.set<furvm::u8>(67)); // He talkin' 'bout sum 6-7 while I want sixty ni-
+    EXPECT_THROW(thing.set<furvm::s32>(1337), furvm::bad_thing_access);
 }
 
 } // namespace