Terminate in throw_exception when exceptions are disabled
#106
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My understanding of `TL_EXPECTED_EXCEPTIONS_ENABLED` is that if exceptions are *disabled*, the code using `expected` must ensure that no attempt is ever made to throw an exception. I think the current implementation of `throw_exception` is problematic because the branch in which exceptions are disabled simply tells the compiler that this code is never reached. This is most likely not true if `throw_exception` actually gets called. Reaching e.g. a `__builtin_unreachable` is undefined behaviour. I suggest that instead of using compiler-specific builtins, the code simply calls `std::terminate`. This seems appropriate, as we pretty much have a case very similar to an uncaught exception. This also solves the problem that `__builtin_unreachable` isn't implemented by a lot of embedded compilers (which is what made me look into this code in the first place).
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There should probably be tests for this behaviour; currently |
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My understanding of
TL_EXPECTED_EXCEPTIONS_ENABLEDis that ifexceptions are disabled, the code using
expectedmust ensurethat no attempt is ever made to throw an exception.
I think the current implementation of
throw_exceptionisproblematic because the branch in which exceptions are disabled
simply tells the compiler that this code is never reached. This
is most likely not true if
throw_exceptionactually gets called.Reaching e.g. a
__builtin_unreachableis undefined behaviour.I suggest that instead of using compiler-specific builtins, the
code simply calls
std::terminate. This seems appropriate, aswe pretty much have a case very similar to an uncaught exception.
This also solves the problem that
__builtin_unreachableisn'timplemented by a lot of embedded compilers (which is what made
me look into this code in the first place).