Streamline exceptions #4
Description
IMPORTANT: before starting implementing it, we have to harmonize it with https://nodejs.org/api/errors.html
Exception Ideology:
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everybody uses nodecpp::error - value-based, alongside P0709 (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0709r0.pdf). It has member error(),
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everybody catches it ONLY by reference (sic!)
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API-wise, alongside P0709, nodespp::error has comparison operators, bunch of static members which represent pre-constructed standard errors (to be trhown and/or compared to), and member error() which returns const char*so that both print("{}",x.error()) is possible.
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standard errors are NOT migrated by default into nodecpp::error, we have to define ALL the errors within nodecpp::error ourselves.
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allocation failure IS an exception (at least for the time being).
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implementation-wise, we want to provide TWO implementations for nodecpp::error (chosen by project-level ≠define):
a. based on std::exception
b. based on https://github.com/ned14/status-code (though probably based on their status_code, NOT on their error classes; in any case we MUST NOT use typedef as we need full control over API)
This will allow us to:
a. provide convenient exception semantics
b. to be future-proof in a sense that whenever P0709 is supported by compilers, end-user will be able to CHOOSE whether they want to have std::exception-based performance or value-based performance - while preserving exactly the same code (the one which we enforce from the very beginning).