修改下属简短而丑陋的程序，使其使用lambda表达式而不是函数符Adder，请不要修改sum（）。
#include <iostream>
#include <array>
const int Size = 5;
template <typename T>
void sum (std::array <double ,Size> a,T&fp);
class Adder
{
double tot;
public;
Adder (double q = 0) :tot (q) {}
void operator () (double w) {tot +=w;)
double tot_v () const {return tot;};
};
int main()
{
double total = 0.0;
Adder ad(total);
std::array<double,Size>temp_c = {32.1,34.3,37.8,35.2,34.7}
sum (temp_c,ad);
total = ad.tot_v();
std::cout << "total:" << ad.tot_v() << '\n';
return 0;
}
template <typename T>
void sum (std::array<double,Size>a,T& fp)
{
for (auto pt = a.begin();pt != a.end(); ++pt)
{
fp(*pt);
}
} 
#include <iostream> #include <array> #include <algorithm> const int Size = 5; template <typename T> void sum (std::array <double ,Size> a,T&fp); int main() { double total = 0.0; std::array<double,Size>temp_c = {32.1,34.3,37.8,35.2,34.7} sum (temp_c,[&total}(double w) {total] += w;}); std::cout << "total:" << total << '\n'; std::cin.get(); return 0; } template <typename T> void sum (std::array<double,Size>a,T& fp) { for (auto pt = a.begin();pt != a.end(); ++pt) { fp(*pt); } }