Re: check for deleted map entry -> crash ?

I'm using an STL map in my code.
My application sometimes tries to delete things twice from the map.
This leads to a crash in my current code. The problem is probably the
way I check whether it is necessary to delete something (line 44 and 52
in below code).
In the below code the problem is demonstrated, line 65 will cause a
segmentation fault.

     1 #include <iostream>
     2 #include <cstdlib>
     3 #include <map>
     4
     5 using namespace std;
     6
     7 class MyClass
     8 {
     9 public:
    10 MyClass(int);
    11 ~MyClass();
    12 void show();
    13 private:
    14 int nr_;
    15 };
    16
    17 MyClass::MyClass(int nr) : nr_(nr)
    18 {
    19 cout << "MyClass: " << nr_ << " constructed" << endl;
    20 }
    21
    22 MyClass::~MyClass()
    23 {
    24 cout << "MyClass: " << nr_ << " destructed" << endl;
    25 }
    26
    27 void MyClass::show()
    28 {
    29 cout << "Show this MyClass: " << nr_ << endl;
    30 }
    31
    32 typedef map<int, MyClass *> RtdmCyclicTimerMap;
    33
    34 int main(void)
    35 {
    36 RtdmCyclicTimerMap cyclicRtdmTimer_;
    37 map<int, MyClass *>::const_iterator cyclicRtdmIt;