在C++ STL的map中保存map：
1 #include <iostream> 2 #include <map> 3 #include <string> 4 5 using namespace std; 6 7 int main() 8 { 9 std::map<int, std::map<std::string, int>* > test_map; 10 std::map<std::string, int>* map_01; 11 for(int i=0; i<10; ++i){ 12 map_01 = new std::map<std::string, int>; 13 test_map.insert(make_pair(i, map_01)); 14 } 15 16 for(std::map<int, std::map<std::string, int>* >::iterator it=test_map.begin(); it!=test_map.end(); ++it){ 17 std::cout << "first " << it->first << std::endl; 18 } 19 20 for(std::map<int, std::map<std::string, int>* >::iterator it = test_map.begin(); 21 it != test_map.end(); ++it){ 22 map_01 = it->second; 23 delete map_01; 24 map_01 = NULL; 25 } 26 27 return 0; 30 } 31 32 root@u18:~/cp/test# g++ map.cpp -g -Wall 33 root@u18:~/cp/test# ./a.out 34 first 0 35 first 1 36 first 2 37 first 3 38 first 4 39 first 5 40 first 6 41 first 7 42 first 8 43 first 9 44 root@u18:~/cp/test# valgrind --tool=memcheck ./a.out 45 ==21868== Memcheck, a memory error detector 46 ==21868== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al. 47 ==21868== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info 48 ==21868== Command: ./a.out 49 ==21868== 50 first 0 51 first 1 52 first 2 53 first 3 54 first 4 55 first 5 56 first 6 57 first 7 58 first 8 59 first 9 60 ==21868== 61 ==21868== HEAP SUMMARY: 62 ==21868== in use at exit: 0 bytes in 0 blocks 63 ==21868== total heap usage: 20 allocs, 20 frees, 960 bytes allocated 64 ==21868== 65 ==21868== All heap blocks were freed -- no leaks are possible 66 ==21868== 67 ==21868== For counts of detected and suppressed errors, rerun with: -v 68 ==21868== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2) 69 root@u18:~/cp/test#