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Re: The C Containers library

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Malcolm McLean wrote:
> On Sunday, November 1, 2015 at 11:50:35 PM UTC, Ben Bacarisse wrote:
>> Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
>>
>> I can see how to simplify the language by removing the type-checking
>> (you use void * and sizes) but then it's not true that problems simply
>> don't arise.  If you keep the idea of types (with all the safety that
>> brings with it) then there is complexity that C can't abstract over.
>>
> It's not all or nothing - "types" or "binary bits". You can allow
> very rich types, like C++.

Or C.

> But then that means that "memcpy(&dest, &src, sizeof(type)) is no
> longer adequate.

Which happens as soon as you have a struct with pointer members and you 
want to maintain some degree of sanity regarding ownership of the 
dynamic memory.

> So you need a "copy constructor". Which means that
> containers need some way of automatically linking to the copy
> constructor. Then you find that, for efficiency, you need a "move
> constructor". You also need a "default constructor" to create
> null objects, which gives rise to the concept of the "null object"
> as well as the "null pointer - all the methods have to react
> appropriately to being passed a null object. The complexities grow.

That's something I've very rarely seen in C++ or C.  If a default 
constructor isn't appropriate, block it.

> A C "vector", however, is simply
>
> struct C_vector
> {
>     unsigned char *base;
>     int N; // number of elements
>     int size; // buffer size
>     size_t elsize; // size of element
> }
>
> then you use memmove and memcpy to keep the contents in an array.
> There's no complexity of constructor calls.

For trivial data types, maybe.  For most real world ones, things will 
get more complicated.

-- 
Ian Collins

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The C Containers library jacobnavia <jacob@jacob.remcomp.fr> - 2015-11-01 10:24 +0100
  Re: The C Containers library Ian Collins <ian-news@hotmail.com> - 2015-11-01 22:43 +1300
    Re: The C Containers library jacobnavia <jacob@jacob.remcomp.fr> - 2015-11-01 12:08 +0100
      Re: The C Containers library Ian Collins <ian-news@hotmail.com> - 2015-11-02 10:46 +1300
        Re: The C Containers library jacobnavia <jacob@jacob.remcomp.fr> - 2015-11-01 23:10 +0100
  Re: The C Containers library gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-01 10:57 +0000
  Re: The C Containers library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 10:57 +0000
    Re: The C Containers library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-01 03:30 -0800
      Re: The C Containers library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 16:36 +0000
        Re: The C Containers library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-01 10:04 -0800
          Re: The C Containers library Ian Collins <ian-news@hotmail.com> - 2015-11-02 07:23 +1300
            Re: The C Containers library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-01 13:25 -0800
            Re: The C Containers library supercat@casperkitty.com - 2015-11-01 15:44 -0800
          Re: The C Containers library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 23:50 +0000
            Re: The C Containers library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 01:19 -0800
              Re: The C Containers library Ian Collins <ian-news@hotmail.com> - 2015-11-02 22:33 +1300
                Re: The C Containers library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 02:04 -0800
  Re: The C Containers library Keith Thompson <kst-u@mib.org> - 2015-11-01 12:04 -0800
    Re: The C Containers library Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-01 15:41 -0500
      Re: The C Containers library Keith Thompson <kst-u@mib.org> - 2015-11-01 13:26 -0800
        Re: The C Containers library Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-01 16:50 -0500

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