std::ranges::views::all_t, std::ranges::views::all

< cpp‎ | ranges
Defined in header <ranges>
template <ranges::viewable_range R>
using all_t = decltype(views::all(std::declval<R>()));
(1) (since C++20)
inline constexpr /*unspecified*/ all = /*unspecified*/;
(2) (since C++20)

A range adaptor that returns a view that includes all elements of its range argument.

The expression views::all(E) is expression-equivalent (has the same effect) to:

[edit] Expression-equivalent

Expression e is expression-equivalent to expression f, if e and f have the same effects, either are both potentially-throwing or are both not potentially-throwing (i.e. noexcept(e) == noexcept(f)), and either are both constant subexpressions or are both not constant subexpressions.

[edit] Example

#include <ranges>
#include <vector>
#include <iostream>
int main()
    std::vector<int> v{0,1,2,3,4,5};
    for(int n : std::views::all(v) | std::views::take(2) ) {
        std::cout << n << ' ';


0 1

[edit] See also

an empty view with no elements
(class template) (variable template) [edit]
a view that contains a single element of a specified value
(class template) (customization point object) [edit]