C++ allows overloading the comma operator. This can be (ab)used to make the following syntax work for, e.g., initializing a vectorish type:

    MyType obj = 1, 2, 3;

Due to the precedence of operators, this is actually equivalent to

    ((MyType obj = 1), 2), 3;

so as long as the overloaded assignment operator returns an object that the comma operator mutates and returns, this can be made the have effect of initializing the declared object to a "list".

This trick is used by Boost Spirit to allow things like (example from http://stackoverflow.com/questions/54142/c-comma-operator)

    keywords = "and", "or", "not", "xor";