Re: [boost] [Boost] [Stacktrace] review

16 Dec 2016

      On Fri, Dec 16, 2016 at 2:05 PM, Andrey Semashev 
wrote:
...
On Sat, Dec 17, 2016 at 12:54 AM, Robert Ramey  wrote:
...
On 12/16/16 12:48 PM, Emil Dotchevski wrote:
...
a function will either succeed or it will not return.
not necessarily
bool f() {
        if ...
                invoke_error
                return failure or ignore error
        ...
        return success
}
if invoke error is mapped to throw exception then it will never return.
If
it's mapped to something else - like emitting an error message or
invoking a
user specified call back then it won't throw an exception.
That results in a really horrible API with dual error reporting mechanisms.
Indeed. Again, enforcing postconditions is the main benefit of throwing.
Specifically:

if( condition-that-code-below-cant-deal-with )
  boost::throw_exception(my_error());
//safe to assume no error occurred because boost::throw_exception does nor
return.

The call to throw_exception is not merely reporting the error but also
protecting the scope that follows.

Emil