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.
