--- name: "__gnu_parallel::_IteratorPair" section: "3" platform: "linux" package: "gcc" version: "16.2.1+r23+gd564253eb6c8-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/__gnu_parallel::_IteratorPair" --- # \_\_gnu\_parallel::\_IteratorPair(3) A pair of iterators. The usual iterator operations are applied to both child iterators. ## NAME \_\_gnu\_parallel::\_IteratorPair\< \_Iterator1, \_Iterator2, \_IteratorCategory \> - A pair of iterators. The usual iterator operations are applied to both child iterators. ## SYNOPSIS \#include \ Inherits **std::pair\< \_Iterator1, \_Iterator2 \>**. ### Public Types typedef **std::iterator\_traits**\< \_Iterator1 \> **\_TraitsType**\ typedef \_TraitsType::difference\_type **difference\_type**\ typedef \_Iterator1 **first\_type**\ The type of the first member. typedef \_IteratorCategory **iterator\_category**\ typedef \_IteratorPair \* **pointer**\ typedef \_IteratorPair & **reference**\ typedef \_Iterator2 **second\_type**\ The type of the second member. typedef void **value\_type**\ ### Public Member Functions **\_IteratorPair** (const \_Iterator1 &\_\_first, const \_Iterator2 &\_\_second)\ constexpr **explicit** (!\_S\_convertible\< \_U1 &, \_U2 & \>()) **pair**(**pair**\< \_U1\ constexpr **explicit** (!\_S\_convertible\< \_U1 &, \_U2 & \>()) **pair**(**pair**\< \_U1\ constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\< \_U1 &, \_U2 & \>()) **pair**(**pair**\< \_U1\ Converting constructor from a non-const pair\ lvalue. constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\< \_U1 &, \_U2 & \>()) **pair**(**pair**\< \_U1\ Converting constructor from a non-const pair\ lvalue. constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(\_U1 &&\ constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(\_U1 &&\ constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(\_U1 &&\_\_x\ Constructor accepting two values of arbitrary types. constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(\_U1 &&\_\_x\ Constructor accepting two values of arbitrary types. constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(**pair**\< \_U1\ constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(**pair**\< \_U1\ constexpr \_U2 &constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(**pair**\< \_U1\ Converting constructor from a non-const pair\ rvalue. constexpr \_U2 &constexpr **explicit** (!\_S\_convertible\< \_U1, \_U2 \>()) **pair**(**pair**\< \_U1\ Converting constructor from a non-const pair\ rvalue. constexpr **explicit** (!\_S\_convertible\< const \_Iterator1 &, const \_Iterator2 & \>()) **pair**(const type\_identity\_t\< \_Iterator1 \> &\_\_x\ Constructor accepting lvalues of first\_type and second\_type. constexpr **explicit** (!\_S\_convertible\< const \_Iterator1 &, const \_Iterator2 & \>()) **pair**(const type\_identity\_t\< \_Iterator1 \> &\_\_x\ Constructor accepting lvalues of first\_type and second\_type. constexpr **explicit** (!\_S\_convertible\< const \_U1 &, const \_U2 & \>()) **pair**(const **pair**\< \_U1\ constexpr **explicit** (!\_S\_convertible\< const \_U1 &, const \_U2 & \>()) **pair**(const **pair**\< \_U1\ constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\< const \_U1 &, const \_U2 & \>()) **pair**(const **pair**\< \_U1\ Converting constructor from a const pair\ lvalue. constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\< const \_U1 &, const \_U2 & \>()) **pair**(const **pair**\< \_U1\ Converting constructor from a const pair\ lvalue. constexpr **explicit** (!\_S\_convertible\< const \_U1, const \_U2 \>()) **pair**(const **pair**\< \_U1\ constexpr **explicit** (!\_S\_convertible\< const \_U1, const \_U2 \>()) **pair**(const **pair**\< \_U1\ constexpr \_U2 &constexpr **explicit** (!\_S\_convertible\< const \_U1, const \_U2 \>()) **pair**(const **pair**\< \_U1\ Converting constructor from a const pair\ rvalue. constexpr \_U2 &constexpr **explicit** (!\_S\_convertible\< const \_U1, const \_U2 \>()) **pair**(const **pair**\< \_U1\ Converting constructor from a const pair\ rvalue. constexpr **explicit** (!\_S\_convertible\_from\_pair\_like\< \_UPair \>()) **pair**(\_UPair &&)=delete\ constexpr **explicit** (!\_S\_convertible\_from\_pair\_like\< \_UPair \>()) **pair**(\_UPair &&)=delete\ constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\_from\_pair\_like\< \_UPair \>()) **pair**(\_UPair &&\_\_p)\ constexpr \_U2 &&constexpr **explicit** (!\_S\_convertible\_from\_pair\_like\< \_UPair \>()) **pair**(\_UPair &&\_\_p)\ constexpr **explicit** (\_\_not\_\< \_\_and\_\< \_\_is\_implicitly\_default\_constructible\< \_Iterator1 \>, \_\_is\_implicitly\_default\_constructible\< \_Iterator2 \> \> \>()) **pair**() noexcept(is\_nothrow\_default\_constructible\_v\< \_Iterator1 \> &&is\_nothrow\_default\_constructible\_v\< \_Iterator2 \>)\ Default constructor. constexpr **explicit** (\_\_not\_\< \_\_and\_\< \_\_is\_implicitly\_default\_constructible\< \_Iterator1 \>, \_\_is\_implicitly\_default\_constructible\< \_Iterator2 \> \> \>()) **pair**() noexcept(is\_nothrow\_default\_constructible\_v\< \_Iterator1 \> &&is\_nothrow\_default\_constructible\_v\< \_Iterator2 \>)\ Default constructor. constexpr \_U2 &&constexpr \_U2 &\_\_p **noexcept** (\_S\_nothrow\_constructible\< \_U1 &, \_U2 & \>())\ constexpr \_U2 &&constexpr \_U2 &\_\_p **noexcept** (\_S\_nothrow\_constructible\< \_U1 &, \_U2 & \>())\ constexpr \_U2 &constexpr \_U2 &&\_\_p **noexcept** (\_S\_nothrow\_constructible\< \_U1, \_U2 \>())\ constexpr \_U2 &constexpr \_U2 &&\_\_p **noexcept** (\_S\_nothrow\_constructible\< \_U1, \_U2 \>())\ constexpr \_U2 &&\_\_y **noexcept** (\_S\_nothrow\_constructible\< \_U1, \_U2 \>())\ constexpr \_U2 &&\_\_y **noexcept** (\_S\_nothrow\_constructible\< \_U1, \_U2 \>())\ constexpr const \_Iterator2 &\_\_y **noexcept** (\_S\_nothrow\_constructible\< const \_Iterator1 &, const \_Iterator2 & \>())\ constexpr const \_Iterator2 &\_\_y **noexcept** (\_S\_nothrow\_constructible\< const \_Iterator1 &, const \_Iterator2 & \>())\ constexpr \_U2 &&constexpr \_U2 &\_\_p **noexcept** (\_S\_nothrow\_constructible\< const \_U1 &, const \_U2 & \>())\ constexpr \_U2 &&constexpr \_U2 &\_\_p **noexcept** (\_S\_nothrow\_constructible\< const \_U1 &, const \_U2 & \>())\ constexpr \_U2 &constexpr \_U2 &&\_\_p **noexcept** (\_S\_nothrow\_constructible\< const \_U1, const \_U2 \>())\ constexpr \_U2 &constexpr \_U2 &&\_\_p **noexcept** (\_S\_nothrow\_constructible\< const \_U1, const \_U2 \>())\ **operator \_Iterator2** () const\ \_IteratorPair **operator+** (difference\_type \_\_delta) const\ \_IteratorPair & **operator++** ()\ const \_IteratorPair **operator++** (int)\ difference\_type **operator-** (const \_IteratorPair &\_\_other) const\ \_IteratorPair & **operator--** ()\ const \_IteratorPair **operator--** (int)\ \_IteratorPair & **operator=** (const \_IteratorPair &\_\_other)\ constexpr void **swap** (const **pair** &\_\_p) const noexcept(\_\_and\_v\< \_\_is\_nothrow\_swappable\< const \_Iterator1 \>, \_\_is\_nothrow\_swappable\< const \_Iterator2 \> \>)\ constexpr void **swap** (const **pair** &\_\_p) const noexcept(\_\_and\_v\< \_\_is\_nothrow\_swappable\< const \_Iterator1 \>, \_\_is\_nothrow\_swappable\< const \_Iterator2 \> \>)\ constexpr void **swap** (**pair** &\_\_p) noexcept(\_\_and\_\< \_\_is\_nothrow\_swappable\< \_Iterator1 \>, \_\_is\_nothrow\_swappable\< \_Iterator2 \> \>::value)\ Swap the first members and then the second members. constexpr void **swap** (**pair** &\_\_p) noexcept(\_\_and\_\< \_\_is\_nothrow\_swappable\< \_Iterator1 \>, \_\_is\_nothrow\_swappable\< \_Iterator2 \> \>::value)\ Swap the first members and then the second members. ### Public Attributes \_Iterator1 **first**\ The first member. \_Iterator1 **first**\ The first member. \_Iterator2 **second**\ The second member. \_Iterator2 **second**\ The second member. ### Related Symbols (Note that these are not member symbols.) constexpr enable\_if\< \_\_and\_\< \_\_is\_swappable\< \_Iterator1 \>, \_\_is\_swappable\< \_Iterator2 \> \>::value \>::type **swap** (**pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, **pair**\< \_Iterator1, \_Iterator2 \> &\_\_y) noexcept(noexcept(\_\_x.swap(\_\_y)))\ constexpr enable\_if\< \_\_and\_\< \_\_is\_swappable\< \_Iterator1 \>, \_\_is\_swappable\< \_Iterator2 \> \>::value \>::type **swap** (**pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, **pair**\< \_Iterator1, \_Iterator2 \> &\_\_y) noexcept(noexcept(\_\_x.swap(\_\_y)))\ constexpr bool **operator==** (const **pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, const **pair**\< \_U1, \_U2 \> &\_\_y)\ Two pairs are equal iff their members are equal. constexpr bool **operator==** (const **pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, const **pair**\< \_U1, \_U2 \> &\_\_y)\ Two pairs are equal iff their members are equal. constexpr common\_comparison\_category\_t\< \_\_detail::\_\_synth3way\_t\< \_Iterator1, \_U1 \>, \_\_detail::\_\_synth3way\_t\< \_Iterator2, \_U2 \> \> **operator\<=\>** (const **pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, const **pair**\< \_U1, \_U2 \> &\_\_y)\ constexpr common\_comparison\_category\_t\< \_\_detail::\_\_synth3way\_t\< \_Iterator1, \_U1 \>, \_\_detail::\_\_synth3way\_t\< \_Iterator2, \_U2 \> \> **operator\<=\>** (const **pair**\< \_Iterator1, \_Iterator2 \> &\_\_x, const **pair**\< \_U1, \_U2 \> &\_\_y)\ ## Detailed Description ### template\ class \_\_gnu\_parallel::\_IteratorPair\< \_Iterator1, \_Iterator2, \_IteratorCategory \>"A pair of iterators. The usual iterator operations are applied to both child iterators. ## Member Typedef Documentation ### typedef \_Iterator1 std::pair\< \_Iterator1, \_Iterator2 \>::first\_type \[inherited\] The type of the first member. ### typedef \_Iterator2 std::pair\< \_Iterator1, \_Iterator2 \>::second\_type \[inherited\] The type of the second member. ## Member Function Documentation ### \_U2 &&constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1 &, \_U2 & \> ()) \[constexpr\], \[inherited\] Converting constructor from a non-const pair\ lvalue. ### \_U2 &&constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1 &, \_U2 & \> ()) \[constexpr\], \[inherited\] Converting constructor from a non-const pair\ lvalue. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1, \_U2 \> ()) && \[constexpr\], \[inherited\] Constructor accepting two values of arbitrary types. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1, \_U2 \> ()) && \[constexpr\], \[inherited\] Constructor accepting two values of arbitrary types. ### \_U2 &constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1, \_U2 \> ()) \[constexpr\], \[inherited\] Converting constructor from a non-const pair\ rvalue. ### \_U2 &constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< \_U1, \_U2 \> ()) \[constexpr\], \[inherited\] Converting constructor from a non-const pair\ rvalue. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_Iterator1 &, const \_Iterator2 & \> ()) const & \[constexpr\], \[inherited\] Constructor accepting lvalues of first\_type and second\_type. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_Iterator1 &, const \_Iterator2 & \> ()) const & \[constexpr\], \[inherited\] Constructor accepting lvalues of first\_type and second\_type. ### \_U2 &&constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_U1 &, const \_U2 & \> ()) const \[constexpr\], \[inherited\] Converting constructor from a const pair\ lvalue. ### \_U2 &&constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_U1 &, const \_U2 & \> ()) const \[constexpr\], \[inherited\] Converting constructor from a const pair\ lvalue. ### \_U2 &constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_U1, const \_U2 \> ()) const \[constexpr\], \[inherited\] Converting constructor from a const pair\ rvalue. ### \_U2 &constexpr std::pair\< \_Iterator1, \_Iterator2 \>::explicit (!\_S\_convertible\< const \_U1, const \_U2 \> ()) const \[constexpr\], \[inherited\] Converting constructor from a const pair\ rvalue. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (\_\_not\_\< \_\_and\_\< \_\_is\_implicitly\_default\_constructible\< \_Iterator1 \>, \_\_is\_implicitly\_default\_constructible\< \_Iterator2 \> \> \> ()) \[inline\], \[constexpr\], \[noexcept\], \[inherited\] Default constructor. ### std::pair\< \_Iterator1, \_Iterator2 \>::explicit (\_\_not\_\< \_\_and\_\< \_\_is\_implicitly\_default\_constructible\< \_Iterator1 \>, \_\_is\_implicitly\_default\_constructible\< \_Iterator2 \> \> \> ()) \[inline\], \[constexpr\], \[noexcept\], \[inherited\] Default constructor. ### void std::pair\< \_Iterator1, \_Iterator2 \>::swap (pair\< \_Iterator1, \_Iterator2 \> & \_\_p) \[inline\], \[constexpr\], \[noexcept\], \[inherited\] Swap the first members and then the second members. ### void std::pair\< \_Iterator1, \_Iterator2 \>::swap (pair\< \_Iterator1, \_Iterator2 \> & \_\_p) \[inline\], \[constexpr\], \[noexcept\], \[inherited\] Swap the first members and then the second members. ## Friends And Related Symbol Documentation ### common\_comparison\_category\_t\< \_\_detail::\_\_synth3way\_t\< \_Iterator1, \_U1 \>, \_\_detail::\_\_synth3way\_t\< \_Iterator2, \_U2 \> \> operator\<=\> (const pair\< \_Iterator1, \_Iterator2 \> & \_\_x, const pair\< \_U1, \_U2 \> & \_\_y) \[related\] Defines a lexicographical order for pairs. For two pairs of comparable types, P is ordered before Q if P.first is less than Q.first, or if P.first and Q.first are equivalent (neither is less than the other) and P.second is less than Q.second. ### common\_comparison\_category\_t\< \_\_detail::\_\_synth3way\_t\< \_Iterator1, \_U1 \>, \_\_detail::\_\_synth3way\_t\< \_Iterator2, \_U2 \> \> operator\<=\> (const pair\< \_Iterator1, \_Iterator2 \> & \_\_x, const pair\< \_U1, \_U2 \> & \_\_y) \[related\] Defines a lexicographical order for pairs. For two pairs of comparable types, P is ordered before Q if P.first is less than Q.first, or if P.first and Q.first are equivalent (neither is less than the other) and P.second is less than Q.second. ### bool operator== (const pair\< \_Iterator1, \_Iterator2 \> & \_\_x, const pair\< \_U1, \_U2 \> & \_\_y) \[related\] Two pairs are equal iff their members are equal. ### bool operator== (const pair\< \_Iterator1, \_Iterator2 \> & \_\_x, const pair\< \_U1, \_U2 \> & \_\_y) \[related\] Two pairs are equal iff their members are equal. ### enable\_if\< \_\_and\_\< \_\_is\_swappable\< \_Iterator1 \>, \_\_is\_swappable\< \_Iterator2 \> \>::value \>::type swap (pair\< \_Iterator1, \_Iterator2 \> & \_\_x, pair\< \_Iterator1, \_Iterator2 \> & \_\_y) \[related\] Swap overload for pairs. Calls std::pair::swap(). **Note** This std::swap overload is not declared in C++03 mode, which has performance implications, e.g. see https://gcc.gnu.org/PR38466 ### enable\_if\< \_\_and\_\< \_\_is\_swappable\< \_Iterator1 \>, \_\_is\_swappable\< \_Iterator2 \> \>::value \>::type swap (pair\< \_Iterator1, \_Iterator2 \> & \_\_x, pair\< \_Iterator1, \_Iterator2 \> & \_\_y) \[related\] Swap overload for pairs. Calls std::pair::swap(). **Note** This std::swap overload is not declared in C++03 mode, which has performance implications, e.g. see https://gcc.gnu.org/PR38466 ## Member Data Documentation ### \_Iterator1 std::pair\< \_Iterator1, \_Iterator2 \>::first \[inherited\] The first member. ### \_Iterator1 std::pair\< \_Iterator1, \_Iterator2 \>::first \[inherited\] The first member. ### \_Iterator2 std::pair\< \_Iterator1, \_Iterator2 \>::second \[inherited\] The second member. ### \_Iterator2 std::pair\< \_Iterator1, \_Iterator2 \>::second \[inherited\] The second member. ## Author Generated automatically by Doxygen for libstdc++ from the source code.