Function SCIPexpriterInit 

pub unsafe extern "C" fn SCIPexpriterInit(
    iterator: *mut SCIP_EXPRITER,
    expr: *mut SCIP_EXPR,
    type_: SCIP_EXPRITER_TYPE,
    allowrevisit: c_uint,
) -> SCIP_RETCODE

initializes an expression iterator

@note If expr is NULL, then iterator will be set into ended-state (SCIPexpriterIsEnd() is TRUE). Useful if following with SCIPexpriterRestartDFS().

If type is DFS, then stopstages will be set to \ref SCIP_EXPRITER_ENTEREXPR. Use SCIPexpriterSetStagesDFS to change this.