RetroSearch Browse

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://en.cppreference.com/w/cpp/language/../error/error_code/../../ranges/subrange/get.html below:

std::ranges::get(std::ranges::subrange) - cppreference.com

(1) (since C++20) (2) (since C++20)

namespace std { using ranges::get; }

(3) (since C++20)

1) Obtains the iterator or sentinel from a subrange lvalue (or a const rvalue) when N == 0 or N == 1, respectively.

2) Same as (1), except that it takes a non-const subrange rvalue.

3)

Overloads

(1,2)

are imported into namespace

std

, which simplifies their usage and makes every

subrange

with a copyable iterator a

pair-like

type.

[edit] Parameters [edit] Return value

1,2) If N is â0â, returns r.begin(). Otherwise (N is 1), returns r.end().

[edit] Example

#include <array>
#include <iostream>
#include <iterator>
#include <ranges>
 
int main()
{
    std::array a{1, -2, 3, -4};
 
    std::ranges::subrange sub_a{std::next(a.begin()), std::prev(a.end())};
    std::cout << *std::ranges::get<0>(sub_a) << ' '   // == *(begin(a) + 1)
              << *std::ranges::get<1>(sub_a) << '\n'; // == *(end(a) - 1)
 
    *std::get<0>(sub_a) = 42; // OK
//  *std::get<2>(sub_a) = 13; // Error: index can only be 0 or 1
}

Output:

[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 3589 C++20 overload (1) copies begin_ if N is â0â, but I might not model copyable added constraints [edit] See also

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4