Mapping C structure to an XML element - c++

Question

Suppose I have a structure in C or C++, such as:
struct ConfigurableElement {
int ID;
char* strName;
long prop1;
long prop2;
...
};
I would like to load/save it to/from the following XML element:
<ConfigurableElement ID="1" strName="namedElem" prop1="2" prop2="3" ... />
Such a mapping can be trivially done in Java/C# or any other language with run-time reflection for the matter. Can it be done in any non-tedious way in C++ with macros/template trickery?
Bonus points for handling nested structures/unions.

Answer 1

The technique you want is called serialization. You may want to read these articles:
http://www.codeproject.com/KB/cpp/xmlserialization.aspx
http://www.codesynthesis.com/products/xsd/ <=== Very close to what you want!
http://www.artima.com/cppsource/xml_data_binding.html
http://www.ibm.com/developerworks/xml/library/x-serial.html
http://www.firstobject.com/xml-serialization-in-c++.htm
EDIT:
There is another option for you: Xmlize provided by Ultimatepp:
http://www.ultimatepp.org/reference$Xmlize.html
http://www.ultimatepp.org/reference$Xmlize$en-us.html
http://www.ultimatepp.org/reference$XmlizeCustomValue$en-us.html
http://www.ultimatepp.org/reference$Xmlize_std$en-us.html
http://www.ultimatepp.org/reference$XML$en-us.html

Answer 2

Tips and tricks always exists. Take a look at Metaresc library https://github.com/alexanderchuranov/Metaresc
It provides interface for types declaration that will also generate meta-data for the type. Based on meta-data you can easily serialize/deserialize objects of any complexity. Out of the box you can serialize/deserialize XML, JSON, XDR, Lisp-like notation, C-init notation.
Here is a simple example:
#include <stdio.h>
#include <stdlib.h>
#include "metaresc.h"
TYPEDEF_STRUCT (host_t,
(char *, host),
int port,
);
TYPEDEF_STRUCT (config_t,
(host_t, local),
(host_t, remote),
(char *, name),
);
int main (int argc, char * argv[])
{
config_t config = {
.local = {
.host = "localhost",
.port = 8080,
},
.remote = {
.host = "google.com",
.port = 80,
},
.name = "service",
};
char * str = MR_SAVE_XML (config_t, &config);
if (str)
{
printf ("%s\n", str);
free (str);
}
return (EXIT_SUCCESS);
}
This program will output
$ ./config
<?xml version="1.0"?>
<config>
<local>
<host>localhost</host>
<port>8080</port>
</local>
<remote>
<host>google.com</host>
<port>80</port>
</remote>
<name>service</name>
</config>
Library works fine for latest gcc and clang.