On Wed, May 31, 2017 at 8:26 AM, David Crayford <dcrayf...@gmail.com> wrote:
> I think I should have used the term object based for non-OO languages.
> Scope based finalization is a sweet spot of C++ with scoped based
> destructors. I'm coding a lot of Java at the moment and having to code
> finally blocks or use the try-with-resources statement is tedious. But my
> point was mainly about polymorphism and how it can be implemented in
> languages that have function pointers. Of course, in a language that has no
> destructors or finalization you have to explicitly call a destructor.
>
> Here is a nifty piece of C++ code that wraps the C stdio FILE structure
> which implements RAII to call fclose() by using a implicit pointer
> operator! It's one of the many C++ features many people are not aware of.
> Props to Jerry Coffin who invented it.
>
> |classfile {typedefFILE*ptr;ptr wrapped_file;public:file(std::string
> const&name,std::string const&mode =std::string("r")):wrapped_fil
> e(fopen(name.c_str(),mode.c_str())){}operatorptr()const{re
> turnwrapped_file;}~file(){if(wrapped_file)fclose(wrapped_file);}};
> -----------------------------------------------------------------------------
> ||file f("myfile.txt","w");if(!f){fprintf(stderr,"Unable to open
> file\n");return0;}fprintf(f,"Hello world");|
>
> ββ
βIt appears to me that the last section, containing code, does not have any
proper line breaks. I can't read it. And I don't know enough C++ to
reformat it. β
--
Windows. A funny name for a operating system that doesn't let you see
anything.
Maranatha! <><
John McKown
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