29 Numerics library [numerics]

29.7 Numeric arrays [numarray]

29.7.5 Class template slice_­array [template.slice.array]

29.7.5.1 Class template slice_­array overview [template.slice.array.overview]

namespace std {
  template <class T> class slice_array {
  public:
    using value_type = T;

    void operator=  (const valarray<T>&) const;
    void operator*= (const valarray<T>&) const;
    void operator/= (const valarray<T>&) const;
    void operator%= (const valarray<T>&) const;
    void operator+= (const valarray<T>&) const;
    void operator-= (const valarray<T>&) const;
    void operator^= (const valarray<T>&) const;
    void operator&= (const valarray<T>&) const;
    void operator|= (const valarray<T>&) const;
    void operator<<=(const valarray<T>&) const;
    void operator>>=(const valarray<T>&) const;

    slice_array(const slice_array&);
    ~slice_array();
    const slice_array& operator=(const slice_array&) const;
    void operator=(const T&) const;

    slice_array() = delete;       // as implied by declaring copy constructor above
  };
}

The slice_­array template is a helper template used by the slice subscript operator

slice_array<T> valarray<T>::operator[](slice);

It has reference semantics to a subset of an array specified by a slice object.

[Example: The expression a[slice(1, 5, 3)] = b; has the effect of assigning the elements of b to a slice of the elements in a. For the slice shown, the elements selected from a are 1, 4, ..., 13. end example]

29.7.5.2 slice_­array assignment [slice.arr.assign]

void operator=(const valarray<T>&) const; const slice_array& operator=(const slice_array&) const;

These assignment operators have reference semantics, assigning the values of the argument array elements to selected elements of the valarray<T> object to which the slice_­array object refers.

29.7.5.3 slice_­array compound assignment [slice.arr.comp.assign]

void operator*= (const valarray<T>&) const; void operator/= (const valarray<T>&) const; void operator%= (const valarray<T>&) const; void operator+= (const valarray<T>&) const; void operator-= (const valarray<T>&) const; void operator^= (const valarray<T>&) const; void operator&= (const valarray<T>&) const; void operator|= (const valarray<T>&) const; void operator<<=(const valarray<T>&) const; void operator>>=(const valarray<T>&) const;

These compound assignments have reference semantics, applying the indicated operation to the elements of the argument array and selected elements of the valarray<T> object to which the slice_­array object refers.

29.7.5.4 slice_­array fill function [slice.arr.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 slice_­array object refers.