On 4/1/07, Alexander Nasonov <alnsn@yandex.ru> wrote:
Hans Larsen wrote:
Hello,
Better is such a big word. You still have to say in which way it is better; readability, efficiency, simplicity, something else? ;-) Readability and simplicity. Compare
std::FILE* f = NULL;
try { f = std::fopen("/etc/passwd", "r"); // ... } finally { if(f) std::fclose(f); }
with
std::FILE* f = std::fopen("/etc/passwd", "r"); scope(exit) { if(f) std::fclose(f); }
// ...
Even without D's scope(exit) syntax it looks appealing
std::FILE* f = std::fopen("/etc/passwd", "r"); BOOST_SCOPE_EXIT(f, (f)) { if(f) std::fclose(f); } BOOST_SCOPE_EXIT_END(f)
Well, I'm very late to this thread of discussion, but I'd like to add my $0.02. Why would we go through so much complexity? Remember the simple and basic principle of RAII? In situations like this, you just make a simple wrapper of the FILE*, with an implementation similar to that of a smart pointer such as the auto_ptr, and let's name it auto_cfile, with a "FILE*&()" operator member function to expose the FILE* it protects: auto_cfile f(std::fopen("/etc/passwd","r")); .... (uses of f as if it were a FILE*) and the FILE* is automatically closed by auto_cfile's dtor when it goes out of scope. No need of a "try ... catch" block at all, much less of "finally," which is an unnecessary addition in C#, IMHO. <snip> --
Alexander Nasonov http://nasonov.blogspot.com
<snip> -- Thanks, Greg