- Nested (not early exit) returns - 3 Updates
- Factory pattern and MIRSA C++ Guidelines on Dynamic Allocation - 1 Update
- Array member initialization, gcc vs. clang - 1 Update
| "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com>: Jul 07 06:09PM +0200 I think this code is just fine, nothing particularly wrong, but I'm concerned I've changed into a mindset where I think so because I don't /see/ how wonderfully clearly it could be expressed otherwise? I remember discussing SESE/SEME with Andrei Alexandrescu over in clc++m once, where I insisted on SESE being more clear and less error prone. That view was, I now think, very much colored by experience maintaining some ugly C code with umpteen-hundred line functions. But anyway I now see things very differently, and I can't recall how I then thought. Is there some natural non-`return` way to code this that isn't needlessly complex or inefficient, perhaps even better in some way? class Key_event_stream : public Non_copyable , public Non_movable { private: Ref_<Event_stream> all_events_ = Event_stream::singleton(); ~Key_event_stream() {} public: auto has_event() const -> bool { for( ;; ) { if( all_events_.has<Key_event>() ) { return true; } else if( all_events_.has<Event>() ) { all_events_.next_event(); // Consume non-key event. } else { return false; } } } auto next_event() -> Key_event { for( ;; ) { Boxed_event result{ all_events_.next_event() }; if( result.pointer_to<Key_event>() != nullptr ) { return *result.pointer_to<Key_event>(); } } } static auto singleton() -> Ref_<Key_event_stream> { static Key_event_stream the_instance; return the_instance; } }; Cheers!, - Alf |
| "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com>: Jul 07 06:12PM +0200 On 07.07.2016 18:09, Alf P. Steinbach wrote: > I think this code is just fine, nothing particularly wrong, but I'm Oh yes, the `if` can be simplified I see just after posting. Sorry 'bout that, :) - Alf |
| "K. Frank" <kfrank29.c@gmail.com>: Jul 07 01:34PM -0700 Hello Alf! On Thursday, July 7, 2016 at 12:11:37 PM UTC-4, Alf P. Steinbach wrote: > ... > I remember discussing SESE/SEME with Andrei Alexandrescu ... All this talk of SESE/SEME reminds me of fortran with its support for multiple entry points into the same subroutine. > Cheers!, > - Alf Cheerio! K. Frank |
| "Öö Tiib" <ootiib@hot.ee>: Jul 07 07:25AM -0700 On Wednesday, 6 July 2016 04:43:30 UTC+3, Mark wrote: > > /Flibble > Do you have a reference or can you provide sample code illustrating > factory design use withouth dynamic freestore-based allocation? Can you be more specific what you see there as a challenge? Reference ... perhaps C++ FAQ ... may be that one: https://isocpp.org/wiki/faq/dtors#placement-new |
| ram@zedat.fu-berlin.de (Stefan Ram): Jul 07 02:42AM >>What do you mean "explicit initializer"? The array is being initialized >>in both cases. >Explicit initializer in the declaration of each constant. The section »12.6.1« of C++ indeed is titled »Explicit initialization«, but the syntactic category is just called »initializer« without »explicit« IIRC. However, the informative annex C uses »explicit or implicit initializer«. I am not sure if I know what an »implicit initializer« is, though. |
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