NAME¶

std::end(std::valarray) - std::end(std::valarray)

Synopsis¶

template< class T > (1) (since C++11)
/* see below */ end( valarray<T>& v );
template< class T > (2) (since C++11)
/* see below */ end( const valarray<T>& v );

The overload of std::end for valarray returns an iterator of unspecified type
referring to the one past the last element in the numeric array.

1) The return type must
* meet the requirements of mutable LegacyRandomAccessIterator,

* model contiguous_iterator, (since C++20)

* have a member type value_type, which is T, and
* have a member type reference, which is T&.
2) The return type must
* meet the requirements of constant LegacyRandomAccessIterator,

* model contiguous_iterator, (since C++20)

* have a member type value_type, which is T, and
* have a member type reference, which is const T&.

The iterator returned from this function is invalidated when the member function
resize() is called on v or when the lifetime of v ends, whichever comes first.

Parameters¶

v - a numeric array

Return value¶

Iterator to one past the last value in the numeric array.

Exceptions¶

May throw implementation-defined exceptions.

Notes¶

Unlike other functions that take std::valarray arguments, end() cannot accept the
replacement types (such as the types produced by expression templates) that may be
returned from expressions involving valarrays: std::end(v1 + v2) is not portable,
std::end(std::valarray<T>(v1 + v2)) has to be used instead.

The intent of this function is to allow range for loops to work with valarrays, not
to provide container semantics.

Example¶

// Run this code

#include <algorithm>
#include <iostream>
#include <valarray>

int main()
{
const std::valarray<char> va
{
'H', 'e', 'l', 'l', 'o',
',', ' ',
'C', '+', '+', '!', '\n'
};

std::for_each(std::begin(va), std::end(va),
[](char c){ std::cout << c; });
}

Output:¶

Hello, C++!

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
1. end() was required to support replacement
LWG 2058 C++11 types 1. not required
2. it was unspecified when the returned 2. specified
iterators will be invalidated

See also¶

std::begin(std::valarray) overloads std::begin
(C++11) (function template)