not1是构造一个与谓词结果相反的一元函数对象，not2是构造一个与谓词结果相反的二元函数对象。
not1：
1 // not1 example
2 #include <iostream> // std::cout
3 #include <functional> // std::not1
4 #include <algorithm> // std::count_if
5
6 struct IsOdd {
7 bool operator() (const int& x) const {return x%2==1;}
8 typedef int argument_type;
9 };
10
11 int main () {
12 int values[] = {1,2,3,4,5};
13 int cx = std::count_if (values, values+5, std::not1(IsOdd()));
14 std::cout << "There are " << cx << " elements with even values.
";
15 return 0;
16 }
not2：
1 // not2 example
2 #include <iostream> // std::cout
3 #include <functional> // std::not2, std::equal_to
4 #include <algorithm> // std::mismatch
5 #include <utility> // std::pair
6
7 int main () {
8 int foo[] = {10,20,30,40,50};
9 int bar[] = {0,15,30,45,60};
10 std::pair<int*,int*> firstmatch,firstmismatch;
11 firstmismatch = std::mismatch (foo, foo+5, bar, std::equal_to<int>());
12 firstmatch = std::mismatch (foo, foo+5, bar, std::not2(std::equal_to<int>()));
13 std::cout << "First mismatch in bar is " << *firstmismatch.second << '
';
14 std::cout << "First match in bar is " << *firstmatch.second << '
';
15 return 0;
16 }
