Visual Studio C++ exceptions not catched - c++11

Question

Using VS2013, in the C++ code below I get a debug assertion when accessing the vector with an out of range index, which is OK (but the catch block is not reached). When running the release version the program runs without the exception being caught. The output is 1 while it should be 0.
#include <iostream>
#include <vector>
#include <stdexcept>
using namespace std;
vector<int> Vector;
void GetException()
try{
int Sum{ 0 };
// Access an element beyond the end of the vector
for( int i = 0; i <= Vector.size(); i++ )
Sum += Vector[i];
}
catch( ... ){
Vector.clear();
}
int _tmain(int argc, _TCHAR* argv[])
{
Vector.push_back( 1 );
GetException();
cout << Vector.size() << endl;
return 0;
}
When I change it to access a nullptr I get in the debug version an error message for an "unhandled exception" and in the release version it crashes on the access. Are there parameters in VS that modify the behaviour of exceptions?
int Sum{ 0 };
void GetException()
try{
int *pSum{ nullptr };
Sum = *pSum;
}
catch( ... ){
Sum = 1;
}
int _tmain(int argc, _TCHAR* argv[])
{
GetException();
cout << Sum << endl;
return 0;
}

Answer 1

This expression Vector[i] (in your first code example) does not throw exceptions (in normal, release builds anyways), it's simply undefined behavior if i is out of bounds.
This expression Vector.at(i) does throw exceptions (in normal, release builds) if i is out of bounds.
If you want to have a std::vector do bounds checking for you, and throw exceptions if an access is out of bounds, then you should use that form. You can't catch the problem if a Vector[i] access is out of bounds.