Understanding Pure Auto Exceptions in C++

Pure Auto Exceptions occur in C++ when an exception is thrown but not caught. This triggers 'std::terminate', leading to program termination without unwinding the stack.

Uncaught exceptions can lead to resource leaks, as destructors for objects on the stack won't execute. It's vital to write exception-safe code to prevent undefined behavior.

C++ relies on 'try', 'catch', and 'throw' keywords for exception handling. The 'catch' block should match the thrown exception type to handle it properly.

Upon an exception, C++ unwinds the stack, calling object destructors. This ensures resource release, unless a pure auto exception interrupts the process prematurely.

Resource Acquisition Is Initialization (RAII) is a paradigm ensuring resource deallocation via object destructors. It's a strategy to prevent leaks during exceptions.

C++11 deprecated 'throw()' specifications, as they didn't guarantee exceptions wouldn't escape. 'noexcept' is now preferred, signaling functions that won't throw.

Exception handling can impact performance due to extra code and stack unwinding. Writing 'noexcept' functions where possible can optimize performance and clarify code intentions.