Abaqus C++ API syntax

Question

I am new to Abaqus C++ API and have question about the syntax.

db_Odb& odb = openOdb("file.odb");
odb_Step& step = odb.steps()["Step-1"];

odb_Instance& instance = 
    odb.rootAssembly().instances()["PART-1-1"];

There are several instances that the syntax is something like odb.steps()["Step-1"].

My question is in odb.steps()["Step-1"]:

• is odb an object?
• is steps() a method of the object?
• what is steps()["str"]? I did not see that in regular C++ syntax.

Answer 1

To answer your questions: Yes, yes, and index operator. It is all standard C++ syntax.

Without knowing the library in question at all, the class might look something like this:

class db_Odb
{
public:
    std::unordered_map< std::string, odb_Step >& steps();
    // ...
};

So odb.steps() returns an indexable object (here I've used a hash map), and then we look up the key in it by appending ["Step-1"], which calls the map's index operator and returns a reference to a single odb_Step instance in that map.