algorithm 01 all_of

template <class InputIterator, class UnaryPredicate>
  bool all_of (InputIterator first, InputIterator last, UnaryPredicate pred);

template<class InputIterator, class UnaryPredicate>
  bool all_of (InputIterator first, InputIterator last, UnaryPredicate pred)
{
  while (first!=last) {
    if (!pred(*first)) return false;
    ++first;
  }
  return true;
}
返回值：所有的元素都满足pred(*first)返回true,或者范围为空。结果返回true。否则返回false

#include <algorithm>
#include <iostream>

int main() {
std::array<int, 8> foo = {1,3,5,7,9,11,13,15};
if(std::all_of(foo.begin(), foo.end(), [](int i){return i%2;}))
std::cout << "all are odd numbers... ";
}