26 Numerics library [numerics]

26.7 Numeric arrays [numarray]

26.7.4 Class slice [class.slice]

26.7.4.1 Overview [class.slice.overview]

namespace std {
  class slice {
  public:
    slice();
    slice(size_t, size_t, size_t);

    size_t start() const;
    size_t size() const;
    size_t stride() const;

    friend bool operator==(const slice& x, const slice& y);
  };
}
The slice class represents a BLAS-like slice from an array.
Such a slice is specified by a starting index, a length, and a stride.253
BLAS stands for Basic Linear Algebra Subprograms. C++ programs may instantiate this class.
See, for example, Dongarra, Du Croz, Duff, and Hammerling: A set of Level 3 Basic Linear Algebra Subprograms; Technical Report MCS-P1-0888, Argonne National Laboratory (USA), Mathematics and Computer Science Division, August, 1988.

26.7.4.2 Constructors [cons.slice]

slice(); slice(size_t start, size_t length, size_t stride); slice(const slice&);
The default constructor is equivalent to slice(0, 0, 0).
A default constructor is provided only to permit the declaration of arrays of slices.
The constructor with arguments for a slice takes a start, length, and stride parameter.
Example
:
slice(3, 8, 2) constructs a slice which selects elements from an array.
— end example
 ]

26.7.4.3 Access functions [slice.access]

size_t start() const; size_t size() const; size_t stride() const;
Returns: The start, length, or stride specified by a slice object.
Complexity: Constant time.

26.7.4.4 Operators [slice.ops]

friend bool operator==(const slice& x, const slice& y);
Effects: Equivalent to:
return x.start() == y.start() && x.size() == y.size() && x.stride() == y.stride();