名前空間
変種
操作

std::prev

提供: cppreference.com
< cpp‎ | iterator

Defined in header <iterator>
template< class BidirIt >

BidirIt prev( BidirIt it,

              typename std::iterator_traits<BidirIt>::difference_type n = 1 );
(C++11およびそれ以降)
イテレータnitth前身を返す.
Original:
Return the nth predecessor of iterator it.
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目次

[編集] パラメータ

it -
イテレータ
Original:
an iterator
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n -
itが降りなければならない要素の数
Original:
number of elements it should be descended
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型の要件
-
BidirItBidirectionalIterator

の要求を満足しなければなりません。

[編集] 値を返します

イテレータnitth前身.
Original:
The nth predecessor of iterator it.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] 可能な実装

template<class BidirIt>
BidirIt prev(BidirIt it, typename std::iterator_traits<BidirIt>::difference_type n = 1)
{
    std::advance(it, -n);
    return it;
}

[編集]

#include <iostream>
#include <iterator>
#include <vector>
 
int main() 
{
    std::vector<int> v{ 3, 1, 4 };
 
    auto it = v.end();
 
    auto pv = std::prev(it, 2);
 
    std::cout << *pv << '\n';
}

出力:

1

[編集] も参照してください

(C++11)
イテレータをインクリメントします
Original:
increment an iterator
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(関数) [edit]
指定された距離によって進歩イテレータ
Original:
advances an iterator by given distance
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(関数) [edit]