/*D
   MPI_T_pvar_get_index - Get the index of a performance variable

Synopsis:
.vb
int MPI_T_pvar_get_index(const char *name, int var_class, int *pvar_index)
.ve

Input Parameters:
+ name - the name of the performance variable (string)
- var_class - the class of the performance variable (integer)

Output Parameters:
. pvar_index - the index of the performance variable (integer)

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_T_ERR_INVALID
.N MPI_T_ERR_INVALID_NAME
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

