Question

I have a space separated file which contains some key->value pairs. These are to be loaded to a structure of the type given below:

#define FV_PARAM1 "A"
#define FV_PARAM2 "B"

parameter_t & parameterFeatureVector (
        parameter_t     & param,
        int             param1,
        int             param2,
) {

    param.addParam(FV_PARAM1, param1);
    param.addParam(FV_PARAM2, param2);

    return param;
}

So to the above, I can pass the following values:

parameterFeatureVector( 10, 20 );

And I would expect the same to get loaded to ‘param’ structure. The above values are taken from the file. How would I go about implementing the same. If the above is not clear, do feel free to get back on it.

Answer 1

I take it you are asking how to translate a name “A” to a specific structure field? If So, C++ has no built-in way of doing that – you have to write a function:

void Add( parameter_t & p, const std::string & name, int value ) {
  if ( name == "A" ) {
      p.param1 = value;
  }
  else if ( name == "B" ) {
      p.param2 = value;
  }
  else if ( .... ) {   // more name tests here
  }

}

However, I would suggest not doing that, and instead use a map:

std::map <std::string, int> params;

you can then say things like:

params["A"] = 42;