NAME¶

std::ranges::transform_view::size - std::ranges::transform_view::size

Synopsis¶

constexpr auto size() requires ranges::sized_range<V>; (since C++20)
constexpr auto size() const requires ranges::sized_range<const V>; (since C++20)

Returns the number of elements.

Returns ranges::size(base_), where base_ is the underlying view.

Parameters¶

(none)

Return value¶

The number of elements.

Notes¶

If V does not model forward_range, size() might not be well-defined after a call to
begin().

Example¶

// Run this code

#include <iostream>
#include <ranges>
#include <string>
#include <cctype>

int main()
{
std::string s{"The length of this string is 42 characters"};
auto tv = std::ranges::transform_view{s, [](char c) -> char {
return std::toupper(c); }
};
for (auto x: tv) { std::cout << x; };
std::cout << "\nsize = " << tv.size() << '\n';
}

Output:¶

THE LENGTH OF THIS STRING IS 42 CHARACTERS
size = 42

See also¶

ranges::size returns an integer equal to the size of a range
(C++20) (customization point object)
ranges::ssize returns a signed integer equal to the size of a range
(C++20) (customization point object)