for循环中删除map中的元素valgrind检测提示error：Invalid read of size 8

废话不多说，先看下面一段代码

#include <iostream>

#include <map>

using namespace std;

class A

{

public:

typedef std::map<int, string> myMap;

void mapInsert(int i, string s)

{

map.insert(std::make_pair(i, s));

}

void deleteMap()

{

for (myMap::iterator it = map.begin(); it != map.end(); ++it)

{

map.erase(it->first);

}

private:

myMap map;

};

int main()

{

A a;

a.mapInsert(1, "1");

a.mapInsert(2, "2");

a.mapInsert(3, "3");

a.mapInsert(4, "4");

a.mapInsert(5, "5");

a.deleteMap();

return 0;

}

上述代码编译运行皆没有问题，但是用valgrind检测会提示错误：

valgrind --tool=memcheck --leak-check=full --track-origins=yes ./test # ~/test

==723953== Memcheck, a memory error detector

==723953== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info

==723953== Command: ./test

==723953==

==723953== Invalid read of size 8

==723953== at 0x3431C69E60: std::_Rb_tree_increment(std::_Rb_tree_node_base*) (tree.cc:60)

==723953== by 0x40131C: std::_Rb_tree_iterator<std::pair<int const, std::string> >::operator++() (in /home/thm/test/test)

==723953== by 0x40117C: A::deleteMap() (in /home/thm/test/test)

==723953== by 0x400F4B: main (in /home/thm/test/test)

==723953== Address 0x4c580b8 is 24 bytes inside a block of size 48 free'd

==723953== at 0x4A06016: operator delete(void*) (vg_replace_malloc.c:480)

==723953== by 0x401E23: __gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<int const, std::string> > >::deallocate(std::_Rb_tree_node<std::pair<int const, std::string> >*, unsigned long) (in /home/thm/test/test)

==723953== by 0x401C99: std::_Rb_tree<int, std::pair<int const, std::string>, std::_Select1st<std::pair<int const, std::string> >, std::less<int>, std::allocator<std::pair<int const, std::string> > >::_M_put_node(std::_Rb_tree_node<std::pair<int const, std::string> >*) (in /home/thm/test/test)

==723953== by 0x401AA6: std::_Rb_tree<int, std::pair<int const, std::string>, std::_Select1st<std::pair<int const, std::string> >, std::less<int>, std::allocator<std::pair<int const, std::string> > >::_M_destroy_node(std::_Rb_tree_node<std::pair<int const, std::string> >*) (in /home/thm/test/test)

==723953== by 0x401729: std::_Rb_tree<int, std::pair<int const, std::string>, std::_Select1st<std::pair<int const, std::string> >, std::less<int>, std::allocator<std::pair<int const, std::string> > >::erase(std::_Rb_tree_iterator<std::pair<int const, std::string> >) (in /home/thm/test/test)

==723953== by 0x40134C: std::map<int, std::string, std::less<int>, std::allocator<std::pair<int const, std::string> > >::erase(std::_Rb_tree_iterator<std::pair<int const, std::string> >) (in /home/thm/test/test)

==723953== by 0x401170: A::deleteMap() (in /home/thm/test/test)

==723953== by 0x400F4B: main (in /home/thm/test/test)

==723953==

==723953== Invalid read of size 8

==723953== at 0x3431C69E80: std::_Rb_tree_increment(std::_Rb_tree_node_base*) (tree.cc:68)

==723953== by 0x40131C: std::_Rb_tree_iterator<std::pair<int const, std::string> >::operator++() (in /home/thm/test/test)

==723953== by 0x40117C: A::deleteMap() (in /home/thm/test/test)

==723953== by 0x400F4B: main (in /home/thm/test/test)

==723953== Address 0x4c580a8 is 8 bytes inside a block of size 48 free'd

==723953== at 0x4A06016: operator delete(void*) (vg_replace_malloc.c:480)