# (Ruby 1.9.1) error: ‘struct RString’ has no memb er named ‘ptr’

**URL:** <https://www.ruby-forum.com/t/ruby-1-9-1-error-a-struct-rstringa-has-no-memb-er-named-a-ptra/164653>\
**Category:** Ruby\
**Created:** [April 3, 2009, 5:36pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-error-a-struct-rstringa-has-no-memb-er-named-a-ptra/164653 "2009-04-03T17:36:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ISSSSaki\_Baz\_C](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/51bf81/32.png) [@ISSSSaki\_Baz\_C](https://www.ruby-forum.com/u/ISSSSaki_Baz_C)\
**Post date:** [April 3, 2009, 5:36pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-error-a-struct-rstringa-has-no-memb-er-named-a-ptra/164653/1 "2009-04-03T17:36:38Z")

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Hi, trying to compile a C extension I get this error in Ruby 1.9.1:

error: ‘struct RString’ has no member named ‘ptr’

The code is:

* * *

#include \<ruby.h\>  
#include \<stdio.h\>

static VALUE my\_method(VALUE self, VALUE arg) {

## char\* name = RSTRING(arg)-\>ptr;

I find in ruby.h:

* * *

## struct RString { struct RBasic basic; union { struct { long len; char \*ptr; union { long capa; VALUE shared; } aux; } heap; char ary[RSTRING\_EMBED\_LEN\_MAX + 1]; } as; };

Perhaps a change from 1.8? How should I access the “ptr” element?  
Thanks.

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<div class="post-metadata">

**Author:** ![ISSSSaki\_Baz\_C](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/51bf81/32.png) [@ISSSSaki\_Baz\_C](https://www.ruby-forum.com/u/ISSSSaki_Baz_C)\
**Post date:** [April 3, 2009, 5:38pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-error-a-struct-rstringa-has-no-memb-er-named-a-ptra/164653/2 "2009-04-03T17:38:58Z")

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2009/4/3 Iñaki Baz C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> static VALUE my\_method(VALUE self, VALUE arg) {
> 
> ## Â Â Â Â char\* name = RSTRING(arg)-\>ptr;

It seems that I mut use:

char\* name = RSTRING\_PTR(arg);

Am I right?

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<div class="post-metadata">

**Author:** ![ISSSSaki\_Baz\_C](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/51bf81/32.png) [@ISSSSaki\_Baz\_C](https://www.ruby-forum.com/u/ISSSSaki_Baz_C)\
**Post date:** [April 3, 2009, 5:44pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-error-a-struct-rstringa-has-no-memb-er-named-a-ptra/164653/3 "2009-04-03T17:44:51Z")

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2009/4/3 Iñaki Baz C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> Â Â Â Â char\* name = RSTRING\_PTR(arg);
> 
> Am I right?

Autoreply: yes 🙂