Most of the discussion about exceptions tries to think about it in abstract terms, which doesn't work. The point of exceptions is a very concrete one: often the code that runs into an error and the code that handles it are separated by ten levels of function calls. Without exceptions, the logic for detecting and passing on the error has to be duplicated in every function in every one of those levels.
Exceptions are arguably the one feature of C++ that isn't just syntax sugar over C, the one feature that makes the language fundamentally more expressive: they reduce a certain kind of code complexity from O(N) to O(1).
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Most of the discussion about exceptions tries to think about it in abstract terms, which doesn't work. The point of exceptions is a very concrete one: often the code that runs into an error and the code that handles it are separated by ten levels of function calls. Without exceptions, the logic for detecting and passing on the error has to be duplicated in every function in every one of those levels.
Exceptions are arguably the one feature of C++ that isn't just syntax sugar over C, the one feature that makes the language fundamentally more expressive: they reduce a certain kind of code complexity from O(N) to O(1).