可以安全地修改std :: pair :: first的成对向量吗？(Safe To Modify std::pair::first in vector of pairs?)

 我目前正在研究一个DNA数据库类，并且我现在将数据库中的每一行与匹配分数（基于编辑距离）和实际的DNA序列本身相关联，在迭代循环中以这种方式首先修改是否安全？ 
 
typedef std::pair<int, DnaDatabaseRow> DnaPairT;
typedef std::vector<DnaPairT>          DnaDatabaseT;

// ....

for(DnaDatabaseT::iterator it = database.begin();
    it != database.end(); it++)
{
    int score = it->second.query(query);
    it->first = score;
}
 
 我这样做的原因是为了让我可以在稍后分数。 我尝试过使用地图并收到有关首先修改的编译错误，但是有没有比此更好的方法来存储所有信息以便稍后进行排序？ 

I'm currently working on a DNA database class and I currently associate each row in the database with both a match score (based on edit distance) and the actual DNA sequence itself, is it safe to modify first this way within an iteration loop?
 
typedef std::pair<int, DnaDatabaseRow> DnaPairT;
typedef std::vector<DnaPairT>          DnaDatabaseT;

// ....

for(DnaDatabaseT::iterator it = database.begin();
    it != database.end(); it++)
{
    int score = it->second.query(query);
    it->first = score;
}
 
The reason I am doing this is so that I can sort them by score later. I have tried maps and received a compilation error about modifying first, but is there perhaps a better way than this to store all the information for sorting later?

原文：https://stackoverflow.com/questions/330186