The main product I work on has a specification that dictates the use of SOAP/XML. So I'm probably more familiar with SOAP than REST (by which I mean JSON/HTTP). Although I don't really delve deep into the RPC code when it can be avoided.
The answer to pretty much all your questions is "depends on the schema". There are XSD (XML Schema Definition) files that you can use to define types. You can define sequences, etc.
Then you can define a WSDL (Web Services Description Language) file which describes the RPC operations, arguments, return types, etc.
After that, you can use something like gSOAP to generate C/C++ out of the WSDL and XSDs. I think Java has a lot more variety in turning a WSDL into code, but last time I looked on the Java side of things it was super confusing. None of the tools seemed to work well together. They would never shut up about beans, and there always seemed to be a bunch of tool specific annotations. Pretty disappointing, and definitely makes me lean towards REST for personal projects, if only from a KISS perspective.
My impression is that SOAP and XML could probably make a much more complex web service than REST (again, abusing the term to mean JSON/HTTP). But after having worked on a pretty confusing contract-first web service, I am kinda jaded about it.
The answer to pretty much all your questions is "depends on the schema". There are XSD (XML Schema Definition) files that you can use to define types. You can define sequences, etc.
Then you can define a WSDL (Web Services Description Language) file which describes the RPC operations, arguments, return types, etc.
After that, you can use something like gSOAP to generate C/C++ out of the WSDL and XSDs. I think Java has a lot more variety in turning a WSDL into code, but last time I looked on the Java side of things it was super confusing. None of the tools seemed to work well together. They would never shut up about beans, and there always seemed to be a bunch of tool specific annotations. Pretty disappointing, and definitely makes me lean towards REST for personal projects, if only from a KISS perspective.
My impression is that SOAP and XML could probably make a much more complex web service than REST (again, abusing the term to mean JSON/HTTP). But after having worked on a pretty confusing contract-first web service, I am kinda jaded about it.