= library !RootTuple =

Starting with release 2018, the code is able to produce particle vector output as a ROOT file.
Here we rely on the library [https://github.com/davidchall/RootTuple RootTuple], which is a lightweight Fortran interface to some existing [https://root.cern.ch/ ROOT] installation.

Unfortunately, the default installation process of '!RootTuple' produces only a 'shared' library (*.so) , which is not usable with GiBUU; here we need a 'static' library (*.a). Therefore some rework is needed.

== The easier way ==

If you have followed the download proceduce for the tar-balls,  
then 
{{{
make buildRootTuple
}}}
should do all the job.

==== In case of troubles ====

We have changed line 10 in file
`GiBUU/libraries/RootTuple/RootTuple-master/src/CMakeLists.txt`
to
{{{
set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17") # [GiBUU]
}}}
since this C standard was needed for the actual ROOT installation.

If your compiler complaints, please check the output of the command `root-config --cflags`. Maybe you can lower the restrictions for your personal ROOT installation to '-std=c++11'.


== The manual way ==

If something goes wrong, you may try to do the manual compilation procedure:

1. Download the source from https://github.com/davidchall/RootTuple

2. Modify the file `RootTuple-master/src/CMakeLists.txt` by changing one line
{{{
add_library (RootTuple SHARED ${RootTuple_SOURCES})
}}}
  to
{{{
add_library (RootTuple STATIC ${RootTuple_SOURCES})
}}}

3. follow the usual given build procedure of '!RootTuple'

  ...here internals to your ROOT installation may enter...

  a. Maybe you have to add in `RootTuple-master/CMakeLists.txt` the line
{{{
set (CMAKE_CXX_FLAGS "-std=c++17")
}}}

  b. If you have errors related to missing `latex2html`, comment out in `RootTuple-master/CMakeLists.txt`
{{{
#add_subdirectory (docs)
}}}

  (We thank Taisiya Mineeva for pointing us to this!)


4. make the library accessible for GiBUU, e.g.:
{{{
cp RootTuple-master/build/src/libRootTuple.a <your/path/to/GiBUU>/objects/LIB/lib/libRootTuple.100.a
}}}
  (Here the '...100...' indicates the version number, which is fixed to be 1.0.0; please do not change!)

After this, a new rebuild of GiBUU (`make renew; make`) should detect the library.