...
Guarantee | Description | Example |
|---|---|---|
Strong | The strong exception safety guarantee is a property of an operation such that, in addition to satisfying the basic exception safety guarantee, if the operation terminates by raising an exception, it has no observable effects on program state. | |
Basic | The basic exception safety guarantee is a property of an operation such that, if the operation terminates by raising an exception, it preserves program state invariants and prevents resource leaks. | Basic Exception Safety |
None | Code that provides neither the strong nor the basic exception safety guarantee is not exception safe. |
Clearly code Code that guarantees strong exception safety also guarantees basic exception safety.
Because all exceptions thrown in an application must be handled, in compliance with ERR50-CPP. Do not abruptly terminate the program, it is critical that thrown exceptions do not leave the program in an indeterminate state where invariants are violated. That is, the program must provide basic exception safety for all invariants, and may choose to provide strong exception safety for some invariants. Whether Whether exception handling is used to control the termination of the program, or to recover from an exceptional situation, a violated invariant leaves the program in a state where graceful continued execution is likely to introduce security vulnerabilities. Thus, code that provides no exception safety guarantee is unsafe and must be considered defective.
...