add double values to LCParameters

[gaede]

BEGINRELEASENOTES

• add support for storing double values in LCParameters
  • used in run, event and collection parameters
  • example

	DoubleVec dv ;
	dv.push_back( 1.111111111111111111111111111111111111111111111111 ) ;
	dv.push_back( 2.222222222222222222222222222222222222222222222222 ) ;
	dv.push_back( 3.333333333333333333333333333333333333333333333333 ) ;
	evt->parameters().setValues( "SomeDoubleNumbers" , dv ) ;

• should resolve Question/feature request: squared matrix element as double instead of float #138

ENDRELEASENOTES

[tmadlener]

Looks good to me. I just have a question about the versioning and how it relates to I/O and some potential improvements (which would probably also apply to other parts of the LCParameters handling)

[tmadlener]

Suggested change

	int nDouble ;
	SIO_DATA( device , &nDouble , 1 ) ;
	EVENT::DoubleVec doubleVec(nDouble) ;
	for(int j=0; j< nDouble ; j++ ) {
	SIO_DATA( device , &doubleVec[j] , 1 ) ;
	}
	EVENT::DoubleVec doubleVec;
	SIO_SDATA(device, doubleVec);

sio should be able to handle vectors as a whole, without having to read each element separately. We do this in podio: https://github.com/AIDASoft/podio/blob/master/src/SIOBlock.cc#L47-L67

[gaede]

You are right of course. I have here intentionally used the same code structure as for the other parameters for 'consistency'. I believe we should create a separate PR and apply this optimization in all streaming handlers...

[tmadlener]

Agreed :) I will create an issue to keep track of it.

[tmadlener]

Suggested change

	SIO_DATA( device , &nDouble , 1 ) ;
	for(int j=0; j< nDouble ; j++ ){
	SIO_SDATA( device, doubleVec[j] ) ;
	}
	SIO_SDATA(device, doubleVec);

See above.