collector collects into each combined value.
\throws InvalidRankException if \a rank is not a valid
registered rank value. */
+ Collector const & operator[](unsigned rank) const;
+ ///< Get child collector
+ /**< This member will return a const reference to the
+ collector collecting \a rank values.
+ \param[in] rank Number of values the requested
+ collector collects into each combined value.
+ \throws InvalidRankException if \a rank is not a valid
+ registered rank value. */
CollectorRange collectors(); ///< List all child collectors
/**< \returns iterator range of child collector
references */