/*D
   MPI_T_cvar_get_info - Get the information about a control variable

Synopsis:
.vb
int MPI_T_cvar_get_info(int cvar_index, char *name, int *name_len,
                        int *verbosity, MPI_Datatype *datatype,
                        MPI_T_enum *enumtype, char *desc, int *desc_len,
                        int *bind, int *scope)
.ve

Input Parameters:
. cvar_index - index of the control variable to be queried, value between $0$ and $num_cvar-1$ (integer)

Input/Output Parameters:
+ name_len - length of the string and/or buffer for name (integer)
- desc_len - length of the string and/or buffer for desc (integer)

Output Parameters:
+ name - buffer to return the string containing the name of the control variable (string)
. verbosity - verbosity level of this variable (integer)
. datatype - mpi datatype of the information stored in the control variable (handle)
. enumtype - optional descriptor for enumeration information (handle)
. desc - buffer to return the string containing a description of the control variable (string)
. bind - type of mpi object to which this variable must be bound (integer)
- scope - scope of when changes to this variable are possible (integer)

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_T_ERR_INVALID_INDEX
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

