How to parse an XML file with RapidXml

I have to parse an XML file in C++. I was researching and found the RapidXml library for this.

I have doubts about doc.parse<0>(xml).

Can xml be an .xml file or does it need to be a string or char *?

If I can only use string or char * then I guess I need to read the whole file and store it in a char array and pass the pointer of it to the function?

Is there a way to directly use a file because I would need to change the XML file inside the code also.

If that is not possible in RapidXml then please suggest some other XML libraries in C++.

Thanks!!!

Ashd