# 26 Numerics library [numerics]

## 26.7 Numeric arrays [numarray]

### 26.7.7 Class template gslice_­array[template.gslice.array]

#### 26.7.7.1 Overview [template.gslice.array.overview]

namespace std { template<class T> class gslice_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; gslice_array(const gslice_array&); ~gslice_array(); const gslice_array& operator=(const gslice_array&) const; void operator=(const T&) const; gslice_array() = delete; // as implied by declaring copy constructor above }; }
This template is a helper template used by the gslice subscript operator
```gslice_array<T> valarray<T>::operator[](const gslice&); ```
It has reference semantics to a subset of an array specified by a gslice object.
Thus, the expression a[gslice(1, length, stride)] = b has the effect of assigning the elements of b to a generalized slice of the elements in a.

#### 26.7.7.2 Assignment [gslice.array.assign]

```void operator=(const valarray<T>&) const; const gslice_array& operator=(const gslice_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 gslice_­array refers.

#### 26.7.7.3 Compound assignment [gslice.array.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 gslice_­array object refers.

#### 26.7.7.4 Fill function [gslice.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 gslice_­array object refers.