std::end(std::valarray)
/* see below */ end( valarray<T>& v );
/* 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.
- meet the requirements of mutable LegacyRandomAccessIterator,
- model
contiguous_iterator,
- have a member type
value_type, which isT, and - have a member type
reference, which isT&.
- meet the requirements of constant LegacyRandomAccessIterator,
- model
contiguous_iterator,
- have a member type
value_type, which isT, and - have a member type
reference, which isconst 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.
[edit] Parameters
[edit] Return value
Iterator to one past the last value in the numeric array.
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] 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.
[edit] Example
#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++!
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2058 | C++11 | 1. end() was required to support replacement types2. it was unspecified when the returned iterators will be invalidated |
1. not required 2. specified |