STD::REFERENCE_WRAPPER(3)

📦
version 16.2.1+r23+gd564253eb6c8 · 12 versions
, in arch rolling, fedora 44

💖 std::reference_wrapper< _Tp > 💖

okay bestie, so this is the manual for std::reference_wrapper< _Tp > from the libstdc++ Library Functions Manual, and it's giving "primary class template for reference_wrapper" energy, which is honestly iconic of it. sit down, grab a strawberry, let's go 🍓

✨ NAME ✨

std::reference_wrapper< _Tp > — the Primary class template for reference_wrapper. yes that's literally what it says, it's the main character and it knows it 👑

🌸 SYNOPSIS 🌸

#include <functional>

🎀 Public Types 🎀

  • typedef _Tp type — that's the type, no notes 💅

🦋 Public Member Functions 🦋

  • ```cpp template<typename _Up, typename = __not_same<_Up>, typename = decltype(reference_wrapper::_S_fun(std::declval<_Up>()))> constexpr reference_wrapper (_Up &&__uref) noexcept(noexcept(reference_wrapper::_S_fun(std::declval< _Up >())))
— the constructor, constexpr, and it's `noexcept` exactly when that `_S_fun` call is `noexcept`. very demure, very conditional 🫶

- **`reference_wrapper (const reference_wrapper &)=default`** — copy constructor, defaulted, it's literally just vibing

- **`constexpr _Tp & get () const noexcept`** — hands you the reference back, constexpr, no-throw, slay

- **`constexpr operator _Tp & () const noexcept`** — implicit conversion to `_Tp &`, constexpr, noexcept, periodt

- ```cpp
template<typename... _Args> constexpr __invoke_result< _Tp &, _Args...
    >::type operator() (_Args &&... __args) const
    noexcept(__is_nothrow_invocable< _Tp &, _Args... >::value)

— call operator! it forwards to the thing you wrapped, returns whatever __invoke_result< _Tp &, _Args... >::type says, and it's noexcept iff __is_nothrow_invocable< _Tp &, _Args... >::value. the way that it's fully generic... 😭

  • reference_wrapper & operator= (const reference_wrapper &)=default — copy assignment, defaulted, moving on 💅

🌈 Friends 🌈

  • constexpr auto operator<=> (reference_wrapper __x, const _Tp &__y)
  • constexpr auto operator<=> (reference_wrapper __x, reference_wrapper __y)
  • constexpr auto operator<=> (reference_wrapper __x, reference_wrapper< const _Tp > __y)
  • constexpr bool operator== (reference_wrapper __x, const _Tp &__y)
  • constexpr bool operator== (reference_wrapper __x, reference_wrapper __y)
  • constexpr bool operator== (reference_wrapper __x, reference_wrapper< const _Tp > __y)

that's the whole spaceship-and-equality friend squad, all constexpr, all iconic ✨

heads up bestie: these are not member symbols, they just hang around the same friend group
  • ```cpp template<typename _Tp> constexpr reference_wrapper< _Tp > ref (_Tp &__t) noexcept
— Denotes a reference should be taken to a variable.

- ```cpp
template<typename _Tp> constexpr reference_wrapper< const _Tp > cref
    (const _Tp &__t) noexcept

— Denotes a const reference should be taken to a variable.

  • ```cpp template<typename _Tp> constexpr reference_wrapper< _Tp > ref (reference_wrapper< _Tp > __t) noexcept
— `std::ref` overload to prevent wrapping a `reference_wrapper`

- ```cpp
template<typename _Tp> constexpr reference_wrapper< const _Tp > cref
    (reference_wrapper< _Tp > __t) noexcept

— std::cref overload to prevent wrapping a reference_wrapper

🌟 Detailed Description 🌟

template<typename _Tp>
    class std::reference_wrapper< _Tp >

"Primary class template for reference_wrapper." that's it, that's the whole detailed description, and honestly? it ate 💅

Denotes a const reference should be taken to a variable. yes bestie, a const one, respectfully 🌸

std::cref overload to prevent wrapping a reference_wrapper. it's a little bouncer at the door like "not today, no double-wrapping in this house" 🙈

Denotes a reference should be taken to a variable. that's the whole job description, and it does it flawlessly ✨

std::ref overload to prevent wrapping a reference_wrapper. same bouncer, different door 🔥

👑 Author 👑

Generated automatically by Doxygen for libstdc++ from the source code. not a human, just a very diligent little robot bestie doing its thing 🤖💖

and that's the whole page, bestie!! this one came to you from the libstdc++ manual, filed under std::refer...pper< _Tp >(3) — yeah they truncated the name, we don't talk about it 😭 — and the footer just says libstdc++ with that same section-3 title. no cap, that's the entire tea. mwah 💅🎀

📦 where this page comes from
  • arch rolling: gcc 16.2.1+r23+gd564253eb6c8-1 · GPL-3.0-or-later WITH GCC-exception-3.1 AND GFDL-1.3-or-later
  • fedora 44: libstdc++-docs 16.2.1-2.fc44
  • fedora 44: libstdc++-docs 16.2.1-3.fc44 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
  • 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms