Re: [boost] Noexcept

Subject: Re: [boost] Noexcept
From: Richard Hodges (hodges.r_at_[hidden])
Date: 2017-06-13 19:25:35

Does anyone actually have a measurable example of real code in which the
unexceptional path induces any more execution overhead than an
optional/variant/outcome return type?

Because when I look at the code generated by gcc et all, I am convinced
that you're solving a non-existant problem when seeking to replace
exceptions.

By all means have a partial return type such as outcome if a failure is to
result in a useful execution path.

But exceptions do not actually add overhead when used to signal actual
exceptions.

At least in the millions of lines of code I have written and read.

R

On 13 Jun 2017 19:01, "Peter Dimov via Boost" <boost_at_[hidden]> wrote:

> Emil Dotchevski wrote:
>
>> If error codes are treated as "the error", then the error domain is
>> limited to a single function. Consider these two functions:
>>
>> int f1(....); //returns 0 on success, 1-f1_error1, 2-f1_error2
>> int f2(....); //returns 0 on success, 1-f2_error1, 2-f2_error2
>>
>> If f2 calls f1, if the error is communicated by an error code, f2 _must_
>> translate the error condition from the domain of f1 errors, to the domain
>> of f2 errors. And this must be done at every level, which introduces many
>> points in the code where subtle errors may occur, and that is in error
>> handling code which is very difficult to test and debug.
>>
>
> That's exactly the problem std::error_code solves, as it's a (code,
> domain) pair, so there's no need to translate.
>
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