29 Numerics library [numerics]

29.6 Numeric arrays [numarray]

29.6.9 Class template indirect_array [template.indirect.array]

29.6.9.4 Fill function [indirect.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 indirect_array object refers.