C++ memory leak dues to win32 structured exception: ACCESS_VIOLATION

An unhandled (and even a handled) exception in C++ (and in most other non-garbage collected languages) can be extremely dangerous. Maybe this is one of the reasons why some C++ projects avoid using exceptions as an error handling mechanism. An unhandled exception basically returns from many function calls until someone handles it unwinding the whole callstack including the stack frame of each function (that contains the incoming params and local vars of functions). If an exception is handled nowhere (and ACCESS_VIOLATION is rarely handled because it isnt useful to handle it) then the exception unwinds the whole callstack. Result: The local vars and incoming parameters of the active function calls (at the time of exception) simply get destroyed (in case of ACCESS_VIOLATION this unwind/destroy doesnt happen if your code is compiled without SEH code generation). This is not a problem in case of local vars and params that don't need extra steps to destroy like in case of int variable or in case of complex classes that are on the stack by value (RAII: if you have SEH turned on) but this can be extremely dangerous for example if you store FILE pointers or handled or other raw C pointers on the stack because those simply get leaked, the exception returns and the rest of the function that would release these handles/pointers will never get executed. If your code is compiled without SEH support then even RAII is useless and you leak even more things.