如何用非平凡的初始值填充向量? [英] How to fill a vector with non-trivial initial values?

问题描述

我知道如何用非平凡的初始值填充std :: vector，例如序列号:

I know how to fill an std::vector with non-trivial initial values, e.g. sequence numbers:

void IndexArray( unsigned int length, std::vector<unsigned int>& v )
{
    v.resize(length);
    for ( unsigned int i = 0; i < length; ++i )
    {
        v[i] = i;
    }
}

但这是一个for循环.是否有一种优雅的方法可以使用stl功能(而使用Boost来不)以更少的代码行来做到这一点?

But this is a for-loop. Is there an elegant way to do this with less lines of code using stl functionality (and not using Boost)?

推荐答案

您可以使用generate算法，以更通用的方式填充容器:

You can use the generate algorithm, for a more general way of filling up containers:

#include <iostream>
#include <algorithm>
#include <vector>

struct c_unique {
   int current;
   c_unique() {current=0;}
   int operator()() {return ++current;}
} UniqueNumber;


int main () {
  vector<int> myvector (8);
  generate (myvector.begin(), myvector.end(), UniqueNumber);

  cout << "\nmyvector contains:";
  for (vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    cout << " " << *it;

  cout << endl;

  return 0;
}

从 cplusplusreference 中毫不客气地将其删除和编辑.

This was shamelessly lifted and edited from cplusplusreference.

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