c++ - STL容器: iterating between two iterators

Question

我将值存储在 std::map 中

我在 map 中找到两个值，并且我想在第一个值到最后一个值之间进行迭代 - 但是 <= 运算符没有实现，所以我不能做这样的事情:

    void foobar(const DatedRecordset& recs, const double startstamp, const double endtstamp)
    {
        DatedRecordsetConstIter start_iter = recs.lower_bound(startstamp), end_iter = recs.lower_bound(endtstamp);

        // Can't do this .... (<= not defined)
        //for (DatedRecordsetConstIter cit = start_iter; cit <= end_iter; cit++ )

        / So have to resort to a hack like this:
        for (DatedRecordsetConstIter cit = start_iter; cit != recs.end(); cit++ ) {
            if ((*cit).first <= (*end_iter).first){
               //do something;
            }
            else
               break;
            }
       }
}

是否有更优雅的方式在两个已知迭代器之间进行迭代？

Answer 1

使用!=而不是<=它会做你想做的事。

void foobar(const DatedRecordset& recs, const double startstamp, const double endtstamp)
{
    DatedRecordsetConstIter start_iter = recs.lower_bound(startstamp),
                            end_iter = recs.upper_bound(endtstamp);

    for (DatedRecordsetConstIter cit = start_iter; cit != end_iter; ++cit) {
    }
}