.TH "std::reverse_iterator< _Iterator >" 3cxx "libstdc++" \" -*- nroff -*- .ad l .nh .SH NAME std::reverse_iterator< _Iterator > .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits \fBstd::iterator< iterator_traits< _Iterator >::iterator_category, iterator_traits< _Iterator >::value_type, iterator_traits< _Iterator >::difference_type, iterator_traits< _Iterator >::pointer, iterator_traits< _Iterator >::reference >\fP\&. .SS "Public Types" .in +1c .ti -1c .RI "\fBusing\fP \fBdifference_type\fP = iter_difference_t< _Iterator >" .br .ti -1c .RI "\fBusing\fP \fBiterator_category\fP = \fB__detail::__clamp_iter_cat\fP< \fBtypename\fP __traits_type::iterator_category, \fBrandom_access_iterator_tag\fP >" .br .ti -1c .RI "\fBusing\fP \fBiterator_concept\fP = __conditional_t< random_access_iterator< _Iterator >, \fBrandom_access_iterator_tag\fP, \fBbidirectional_iterator_tag\fP >" .br .ti -1c .RI "\fBtypedef\fP _Iterator \fBiterator_type\fP" .br .ti -1c .RI "\fBtypedef\fP __traits_type::pointer \fBpointer\fP" .br .ti -1c .RI "\fBusing\fP \fBreference\fP = iter_reference_t< _Iterator >" .br .ti -1c .RI "\fBusing\fP \fBvalue_type\fP = iter_value_t< _Iterator >" .br .in -1c .SS "Public Member Functions" .in +1c .ti -1c .RI "constexpr \fBreverse_iterator\fP () noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP (const \fBreverse_iterator\fP &__x) noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "template<\fBtypename\fP _Iter > .br requires __convertible<_Iter>constexpr \fBreverse_iterator\fP (const \fBreverse_iterator\fP< _Iter > &__x) noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP (iterator_type __x) noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "constexpr iterator_type \fBbase\fP () const noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "constexpr \fBreference\fP \fBoperator*\fP () const" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP \fBoperator+\fP (\fBdifference_type\fP __n) const" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP & \fBoperator++\fP ()" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP \fBoperator++\fP (int)" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP & \fBoperator+=\fP (\fBdifference_type\fP __n)" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP \fBoperator\-\fP (\fBdifference_type\fP __n) const" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP & \fBoperator\-\-\fP ()" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP \fBoperator\-\-\fP (int)" .br .ti -1c .RI "constexpr \fBreverse_iterator\fP & \fBoperator\-=\fP (\fBdifference_type\fP __n)" .br .ti -1c .RI "constexpr pointer \fBoperator\->\fP () const" .br .ti -1c .RI "\fBreverse_iterator\fP & \fBoperator=\fP (const \fBreverse_iterator\fP &)=\fBdefault\fP" .br .ti -1c .RI "template<\fBtypename\fP _Iter > .br requires __convertible<_Iter> && assignable_from<_Iterator&, const _Iter&>constexpr \fBreverse_iterator\fP & \fBoperator=\fP (const \fBreverse_iterator\fP< _Iter > &__x) noexcept(/*\fBconditional\fP */)" .br .ti -1c .RI "constexpr \fBreference\fP \fBoperator[]\fP (\fBdifference_type\fP __n) const" .br .in -1c .SS "Protected Types" .in +1c .ti -1c .RI "\fBtypedef\fP \fBiterator_traits\fP< _Iterator > \fB__traits_type\fP" .br .in -1c .SS "Protected Attributes" .in +1c .ti -1c .RI "_Iterator \fBcurrent\fP" .br .in -1c .SS "Friends" .in +1c .ti -1c .RI "constexpr iter_rvalue_reference_t< _Iterator > \fBiter_move\fP (const \fBreverse_iterator\fP &__i) noexcept(is_nothrow_copy_constructible_v< _Iterator > &&noexcept(ranges::iter_move(\-\-\fBstd::declval\fP< _Iterator & >())))" .br .ti -1c .RI "template _Iter2> constexpr \fBvoid\fP \fBiter_swap\fP (const \fBreverse_iterator\fP &__x, const \fBreverse_iterator\fP< _Iter2 > &\fB__y\fP) noexcept(is_nothrow_copy_constructible_v< _Iterator > &&is_nothrow_copy_constructible_v< _Iter2 > &&noexcept(ranges::iter_swap(\-\-\fBstd::declval\fP< _Iterator & >(), \-\-\fBstd::declval\fP< _Iter2 & >())))" .br .in -1c .SH "Detailed Description" .PP .SS "template<\fBtypename\fP _Iterator> .br class std::reverse_iterator< _Iterator >"Bidirectional and random access iterators have corresponding reverse iterator adaptors that iterate through the data structure in the opposite direction\&. They have the same signatures as the corresponding iterators\&. The fundamental relation between a reverse iterator and its corresponding iterator \fCi\fP is established by the identity: .PP .nf &*(reverse_iterator(i)) == &*(i \- 1) .fi .PP .PP \fIThis mapping is dictated by the fact that while there is always a pointer past the end of an array, there might not be a valid pointer before the beginning of an array\&.\fP [24\&.4\&.1]/1,2 .PP Reverse iterators can be tricky and surprising at first\&. Their semantics make sense, however, and the trickiness is a side effect of the requirement that the iterators must be safe\&. .SH "Constructor & Destructor Documentation" .PP .SS "template<\fBtypename\fP _Iterator > constexpr \fBstd::reverse_iterator\fP< _Iterator >::reverse_iterator ()\fC [inline]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP" The default constructor value-initializes member \fCcurrent\fP\&. If it is a pointer, that means it is zero-initialized\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBstd::reverse_iterator\fP< _Iterator >::reverse_iterator (iterator_type __x)\fC [inline]\fP, \fC [explicit]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP" This iterator will move in the opposite direction that \fCx\fP does\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBstd::reverse_iterator\fP< _Iterator >::reverse_iterator (const \fBreverse_iterator\fP< _Iterator > & __x)\fC [inline]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP" The copy constructor is normal\&. .SS "template<\fBtypename\fP _Iterator > template<\fBtypename\fP _Iter > .br requires __convertible<_Iter>constexpr \fBstd::reverse_iterator\fP< _Iterator >::reverse_iterator (const \fBreverse_iterator\fP< _Iter > & __x)\fC [inline]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP" A reverse_iterator across other types can be copied if the underlying iterator can be converted to the type of \fCcurrent\fP\&. .SH "Member Function Documentation" .PP .SS "template<\fBtypename\fP _Iterator > constexpr iterator_type \fBstd::reverse_iterator\fP< _Iterator >::base () const\fC [inline]\fP, \fC [constexpr]\fP, \fC [noexcept]\fP" .PP \fBReturns\fP .RS 4 \fCcurrent\fP, the iterator used for underlying work\&. .RE .PP .SS "template<\fBtypename\fP _Iterator > constexpr \fBreference\fP \fBstd::reverse_iterator\fP< _Iterator >::operator* () const\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 A reference to the value at \fC--current\fP .RE .PP This requires that \fC--current\fP is dereferenceable\&. .PP \fBWarning\fP .RS 4 This implementation requires that for an iterator of the underlying iterator type, \fCx\fP, a reference obtained by \fC*x\fP remains valid after \fCx\fP has been modified or destroyed\&. This is a bug: http://gcc.gnu.org/PR51823 .RE .PP .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP \fBstd::reverse_iterator\fP< _Iterator >::operator+ (\fBdifference_type\fP __n) const\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 A reverse_iterator that refers to \fCcurrent\fP - \fI__n\fP .RE .PP The underlying iterator must be a Random Access Iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP & \fBstd::reverse_iterator\fP< _Iterator >::operator++ ()\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 \fC*this\fP .RE .PP Decrements the underlying iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP \fBstd::reverse_iterator\fP< _Iterator >::operator++ (int)\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 The original value of \fC*this\fP .RE .PP Decrements the underlying iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP & \fBstd::reverse_iterator\fP< _Iterator >::operator+= (\fBdifference_type\fP __n)\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 *this .RE .PP Moves the underlying iterator backwards \fI__n\fP steps\&. The underlying iterator must be a Random Access Iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP \fBstd::reverse_iterator\fP< _Iterator >::operator\- (\fBdifference_type\fP __n) const\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 A reverse_iterator that refers to \fCcurrent\fP - \fI__n\fP .RE .PP The underlying iterator must be a Random Access Iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP & \fBstd::reverse_iterator\fP< _Iterator >::operator\-\- ()\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 \fC*this\fP .RE .PP Increments the underlying iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP \fBstd::reverse_iterator\fP< _Iterator >::operator\-\- (int)\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 A reverse_iterator with the previous value of \fC*this\fP .RE .PP Increments the underlying iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreverse_iterator\fP & \fBstd::reverse_iterator\fP< _Iterator >::operator\-= (\fBdifference_type\fP __n)\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 *this .RE .PP Moves the underlying iterator forwards \fI__n\fP steps\&. The underlying iterator must be a Random Access Iterator\&. .SS "template<\fBtypename\fP _Iterator > constexpr pointer \fBstd::reverse_iterator\fP< _Iterator >::operator\-> () const\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 A pointer to the value at \fC--current\fP .RE .PP This requires that \fC--current\fP is dereferenceable\&. .SS "template<\fBtypename\fP _Iterator > constexpr \fBreference\fP \fBstd::reverse_iterator\fP< _Iterator >::operator[] (\fBdifference_type\fP __n) const\fC [inline]\fP, \fC [constexpr]\fP" .PP \fBReturns\fP .RS 4 The value at \fCcurrent\fP - \fI__n\fP - 1 .RE .PP The underlying iterator must be a Random Access Iterator\&. .SH "Author" .PP Generated automatically by Doxygen for libstdc++ from the source code\&.