有时,我需要一些functor-helper来操作列表.我尽量将范围保持在本地范围内.
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
struct Square
{
int operator()(int x)
{
return x*x;
}
};
int a[5] = {0,1,2,3,4};
int b[5];
transform(a,a+5,b,Square());
for(int i=0; i<5; i++)
cout<<a[i]<<" "<<b[i]<<endl;
}
hello.cpp: In function ‘int main()’: hello.cpp:18:34: error: no matching function for call to ‘transform(int [5],int*,int [5],main()::Square)’
如果我将Square移出main(),那没关系.
