如何通过任意列动态排序数据 [英] How to dynamically sort data by arbitrary column(s)

问题描述

有一个结构（STL，Boost等）组合的数据结构，这将允许我对内存中的数据排序，就像这里的表格中做的 http://en.wikipedia.org/wiki/List_of_cities_proper_by_population



我想要一个通用的解决方案，可以处理任意数字和列名称。基本上类似
到你使用sql的 order by子句

Is there a data structure of combination of structures ( STL, Boost etc. ) that would allow me to sort data in memory like it is done in this table here http://en.wikipedia.org/wiki/List_of_cities_proper_by_population

I would like a generic solution that can handle arbitray number and names of columns. Essentially similar to what you get using sql's order by clause

推荐答案

允许使用结构或元组来保存aa行：

Consder making a struct or tuple to hold a a row:

struct row{
   unsigned rank;
   std::string city;
   double area;
   //so on
}; 

用您的行填充向量或其他容器。

On populate a vector or other contain with your rows.

std::vector<row> rows;

使用 std :: sort 自定义比较函数，你看一些值。

To sort use std::sort with custom comparison function which you look at certain values.

std::sort(rows.begin(), rows.end(), [](const row& r1, const row& r2)->bool{
    return r1.area < r2.area;
}); //sort by area

这可以通过使用矢量向量和比较函数从它的环境中捕获可变数据：参见我的其他答案

This could be made generic by having a vector of vectors and the comparison function could capture a varaible from it's enviroment: see my other answer

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