Conversion of Enum to String

Development Programming & Scripting C++
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17

Throwing my 2 cents here i’ve came with the following:

template<typename T>
static FString EnumToString(T Enum);

It only requires the enum type (absolutely no string and value). It can be used like this:

UYourFunctionLibrary::EnumToString<EBlockMode>(Mode);

Visual studio implementation (in GCC you can use PRETTY_FUNCTION)

template<typename T>
	static FString EnumToString(T Enum)
	{
#if !WITH_EDITOR
		return "";
#else
		static FString EnumName;
		static bool bEnumNameInit = false;

		// Init it once
		if (bEnumNameInit == false)
		{
			bEnumNameInit = true;

			FString FunctionSignature(__FUNCSIG__);
			UE_LOG(LogRPG, Display, TEXT("Enum funcsig: [%s]"), *FunctionSignature);

			int32 FirstIDX = FunctionSignature.Find(TEXT("(enum "), ESearchCase::CaseSensitive, ESearchDir::FromEnd);

			if (FirstIDX != INDEX_NONE)
			{
				FirstIDX = FirstIDX + 6;
				int32 LastIDX = (FunctionSignature.Len() - 1);

				if (FunctionSignature.IsValidIndex(FirstIDX) && FunctionSignature.IsValidIndex(LastIDX) && FirstIDX < LastIDX)
				{
					EnumName = FunctionSignature.Mid(FirstIDX, LastIDX - FirstIDX);
					UE_LOG(LogRPG, Display, TEXT("Enum name: [%s]"), *EnumName);
				}
			}
		}

		if (EnumName.IsEmpty())
			return FString("ENUM_Invalid");
		
		// const UEnum* EnumPtr = FindObject<UEnum>(ANY_PACKAGE, (const TCHAR *)(typeid(T).name()), true);
		const UEnum* EnumPtr = FindObject<UEnum>(ANY_PACKAGE, *EnumName, true);
		if (!EnumPtr)
			return FString("ENUM_Invalid");

		#pragma warning(disable: 4996)
		return EnumPtr->GetDisplayNameText(static_cast<int32>(Enum)).ToString();
#endif
}

I’m sure there’s some template master out there that can transform the usage of FUNCSIG into a constexpr, but the enum name is extracted only once. Note that I’m using it for debugging only, high performance is not a top priority for me.