Re: static constants in a class

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From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.lang.c++
Subject	Re: static constants in a class
Date	Thu, 15 Sep 2011 21:17:46 +1200
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On 09/15/11 08:50 PM, Alain Ketterlin wrote:
> Urs Thuermann<urs@isnogud.escape.de>  writes:
>
>> How should one define a constant, say of type int, in a class?  The
>> only way that worked for me in all cases is to delcare the constant in
>> the class in the header file and define its value in the
>> implementation file:
>>
>> ---- foo.hh ----
>>      class Foo {
>>      public:
>>      	static const int N;
>>      	...
>>      };
>> ---- foo.cc ----
>>      #include "foo.hh"
>>      const int Foo::N = 10;
>> ----------------
> [...]
>
> Make it a inline static method:
>
>      class Foo {
>          ...
>          inline static int N() { return 10; }
>          ...
>      };

The inline is unnecessary, but even without it the solution isn't valid: 
Foo::N() isn't a compile time constant.

-- 
Ian Collins

Thread

static constants in a class Urs Thuermann <urs@isnogud.escape.de> - 2011-09-14 23:43 +0200
  Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-15 10:21 +1200
  Re: static constants in a class Leigh Johnston <leigh@i42.co.uk> - 2011-09-15 00:06 +0100
    Re: static constants in a class Leigh Johnston <leigh@i42.co.uk> - 2011-09-15 00:16 +0100
  Re: static constants in a class Juha Nieminen <nospam@thanks.invalid> - 2011-09-15 06:46 +0000
  Re: static constants in a class Marc <marc.glisse@gmail.com> - 2011-09-15 07:59 +0000
    Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-15 20:09 +1200
      Re: static constants in a class Marc <marc.glisse@gmail.com> - 2011-09-15 08:11 +0000
        Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-15 21:20 +1200
          Re: static constants in a class Marc <marc.glisse@gmail.com> - 2011-09-15 14:03 +0000
            Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-16 09:32 +1200
              Re: static constants in a class Marc <marc.glisse@gmail.com> - 2011-09-16 04:28 +0000
  Re: static constants in a class Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2011-09-15 10:50 +0200
    Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-15 21:17 +1200
      Re: static constants in a class Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2011-09-15 11:48 +0200
      Re: static constants in a class Christopher <cpisz@austin.rr.com> - 2011-09-15 14:24 -0700
        Re: static constants in a class Ian Collins <ian-news@hotmail.com> - 2011-09-16 09:32 +1200
          Re: static constants in a class Leigh Johnston <leigh@i42.co.uk> - 2011-09-15 22:54 +0100
  Re: static constants in a class TonyO <guinness.tony@gmail.com> - 2011-09-15 02:50 -0700

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