29 Numerics library [numerics]

29.7 Numeric arrays [numarray]

29.7.8 Class template mask_­array [template.mask.array]

29.7.8.4 mask_­array fill function [mask.array.fill]

void operator=(const T&) const;

This function has reference semantics, assigning the value of its argument to the elements of the valarray<T> object to which the mask_­array object refers.