Convert FString to std::string

Development Programming & Scripting
1

I am trying to use a JSON library in my code. I am still grasping very basics as I am total rookie with C++. I have a trouble of converting FString to std::string. I did found this wiki page, but for some reason I am getting bunch of japanese(?) characters as the result.

I’ve made this function which is correctly recognized by the json library to do the conversion. However I am sensing there is something not quiet right about it.

void to_json(json& j, const FString& value) {
	j = TCHAR_TO_UTF8(*value);
}

Here is the GitHub issue where I have been discussing this. Any idea what might be wrong please?

Edit

Actually I tried this without interference of the JSON lib and it behaves same way.

FString test = TEXT("MyTest");
std::string test2 = std::string(TCHAR_TO_UTF8(*test));
UE_LOG(LogTemp, Warning, TEXT("JSON %s"), test2.c_str());

Would produce following log statement: LogTemp:Warning: JSON 祍敔瑳

1 Like
2

The problem with your second example is that TEXT("JSON %s") doesn’t expect what you fed it. Try giving it a pointer to an FString like this:

 FString test = "MyTest";
 std::string test2 = std::string(TCHAR_TO_UTF8(*test));
 UE_LOG(LogTemp, Warning, TEXT("JSON %s"), *FString(test2.c_str()));

Also, there is no need for the first TEXT() macro.

5 Likes
3

Thanks for your answer, although a little bit late as I’ve given up and bought JSON plugin for UE which works great. This might come in handy later perhaps.

4

This is nice… if you want to destroy any character different from a-z…
To preserve the characters to revert from string to fstring
----> FString(UTF8_TO_TCHAR(test2.c_str()))