std::list::assign_range(3)

✨ NAME ✨

std::list::assign_range — std::list::assign_range. That’s the whole NAME, bestie. This is the std::list::assign_range(3) page from the C++ Standard Libary (yes, that’s how the manual name is spelled here 💅).

---

🌸 Synopsis 🌸

template< container-compatible-range<T> R >  (since C++23)
void assign_range( R&& rg );

Ok so picture this: assign_range replaces the elements in the container with a copy of each element in rg. That’s the main-character move. ✨

It invalidates all iterators, pointers and references to the elements. All of them. No survivors, bestie 😭.

Each iterator in the range rg is dereferenced exactly once. Periodt.

⚠️ The behavior is undefined if rg overlaps with the container. Like, do not do that. 🫶

---

🎀 Parameters 🎀

• rg — an input_range with reference type convertible to the element type of the container.

---

🧚 Type requirements 🧚

• std::assignable_from<T&, ranges::range_reference_t<R>> must be modeled. Otherwise, the program is ill-formed.
• T must be EmplaceConstructible into the container from *ranges::begin(rg). Otherwise, the behavior is undefined.

---

💫 Return value 💫

(none) — literally nothing returned, bestie.

---

📝 Notes 📝

Feature-test macro check, iykyk 👑

• Feature-test macro: __cpp_lib_containers_ranges
• Value: 202202L
• Std: (C++23)
• Feature: Ranges-aware construction and insertion

---

💻 Example 💻

Run this code, bestie:

// Run this code

#include <algorithm>
#include <cassert>
#include <list>
#include <vector>

int main()
{
    const auto source = std::vector{2, 7, 1};
    auto destination = std::list{3, 1, 4};
#ifdef __cpp_lib_containers_ranges
    destination.assign_range(source);
#else
    destination.assign(source.cbegin(), source.cend());
#endif
    assert(std::ranges::equal(source, destination));
}

---

👀 See also 👀

• insert_range — inserts a range of elements; (C++23); public member function.
• prepend_range — adds a range of elements to the beginning; (C++23); public member function.
• append_range — adds a range of elements to the end; (C++23); public member function.
• assign — assigns values to the container; public member function.

---

That’s the whole page, bestie 💖 — source/version: http://cppreference.com, date: 2024.06.10, page: std::list::assign_range(3). bye 🦋🎀