From: Nikolai Weibull <now@...>
Date: 2010-07-09T18:28:48+09:00
Subject: [ruby-core:31149] Re: Why is there no standard way of creating a 	String from a char *?

On Fri, Jul 9, 2010 at 06:20, Urabe Shyouhei <shyouhei@ruby-lang.org> wrote:
> (2010/07/09 7:04), Nikolai Weibull wrote:

>> Why is there no standard way of creating a String from a char *? ��All
>> the rb_str_new* functions take a const char * and copy it. ��I would
>> like a function that would create a String from a char *, that is,
>> without copying it.

> Because there is GC. ��You can't say if a string content should be freed or not
> when you allow such creation. ��If you need a non-copying region of a memory
> that should not be called a String.

Perhaps I was unclear in my problem description.  If I have a freshly
allocated char * that I get from a library call, why shouldn���t I be
able to use it as the basis of a Ruby String?  I mean, currently I
have to do

int length;
char *result = library_call(���, &length, ���);
VALUE rbresult = rb_str_new(result, length);
free(result);
return rbresult;

I own result, so after creating rbresult I currently have to
immediately free it.  I realize that this doesn���t really matter at all
for small strings, but say that library_call() returns the contents of
an arbitrarily large file.  Copying result inside rb_str_new seems to
me to be a total waste of energy.