- enum initialization - 5 Updates
- Christian, how much do you hate people? - 1 Update
| JiiPee <no@notvalid.com>: Nov 09 07:41PM Is the a way to initialize enum values so that the end result would be: enum class MyOpt {opt1=1, opt2=2, opt3=4, opt4=8}; // etc....multiplied by 2 Yes I can do it manually, but I would like to do it automatically maybe with a function or something (reducing human error). Or the only way to do it is to hardcode like that? I need this in my flags system where I need values 1,2,4,8,16,... |
| "James R. Kuyper" <jameskuyper@verizon.net>: Nov 09 03:07PM -0500 On 2017-11-09 14:41, JiiPee wrote: > Is the a way to initialize enum values so that the end result would be: > enum class MyOpt {opt1=1, opt2=2, opt3=4, opt4=8}; // etc....multiplied by 2 > Yes I can do it manually, but I would like to do it automatically maybe This is about as close as you can get to doing it automatically: enum class MyOpt {opt1=1, opt2, opt3=opt2*2, opt4=opt3*2}; |
| "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com>: Nov 09 09:20PM +0100 On 11/9/2017 8:41 PM, JiiPee wrote: > with a function or something (reducing human error). > Or the only way to do it is to hardcode like that? > I need this in my flags system where I need values 1,2,4,8,16,... Two possible alternatives: * Define `operator|` that adds the necessary `1<<n`. * Use a `std::bitset`. Cheers & hth., - Alf |
| JiiPee <no@notvalid.com>: Nov 09 08:23PM Thanks, but just thinking another thing: is is a good idea at all using enums as (option) flags? I read some say online that should use constants instead. On 09/11/2017 20:20, Alf P. Steinbach wrote: |
| Ian Collins <ian-news@hotmail.com>: Nov 10 09:28AM +1300 On 11/10/2017 09:23 AM, JiiPee wrote: > Thanks, but just thinking another thing: is is a good idea at all using > enums as (option) flags? I read some say online that should use > constants instead. The arguments are less clear now that with have typed enums! Before C++11 a good case could be made for constants given enums always had an underlying type of int. Now we can specify the type, I think enums are a better choice. -- Ian. |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Nov 09 05:37AM -0800 Christian: You know judgment for sin looms over every human soul, yet you remain silent? You do not actively warn the people of their ABSOLUTE NEED to come to Jesus and ask forgiveness for sin? How much do you hate people to leave them ignorantly on the road to Hell? You should be ashamed of yourself! -- Rick C. Hodgin |
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