How to load XML file from url with pugixml

I'm trying to load an XML file from an URL using pugixml parser. The problem is that if you want to load a file from URL you have to load it from memory which it's very confusing for me. This is what I've tried and it doesn't work:

char* source = "http://some_url.xml";
int size = 256;
char* buffer = new char[size];

memcpy(buffer, source, size);

pugi::xml_document doc;
doc.load_buffer_inplace(buffer, size);
...
delete[] buffer;

Here is their documentation: https://pugixml.org/docs/manual.html#loading.memory

Can someone who is more familiar with that stuff please give me an example of how to do it.

If anyone is interested.. this is how I solved it:

const char* f = "new_file.xml";
if (curl){
    const char* c_url = "some_url";

    FILE* ofile = fopen(f, "wb");
    if (!ofile) { fprintf(stderr, "Failed to open file: %s\n", strerror(errno)); }

    if (ofile){
        curl_easy_setopt(curl, CURLOPT_URL, c_url);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, ofile);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeData);
        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);

        curl_easy_perform(curl);

        fclose(ofile);
    }
}
pugi::xml_document doc;
doc.load_file(f);

Thanks for all the help guys!