Perfect! Now I understand the methodology to implement setter for a
structure. Do you think it would make sense to have a macro for this?  Say,
_MEMBER_SET_CHAR.

-Pavlo Solntsev
---------------------------------------------------------------------------------------------

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On Fri, Feb 23, 2018 at 9:43 AM, Kjell Ahlstedt <kjellahlst...@gmail.com>
wrote:

> Den 2018-02-23 kl. 15:36, skrev Pavlo Solntsev:
>
> >>>  Your concern is justified. The Glib::ustring must be returned by
> value. The _MEMBER_GET should be
> It is interesting. getter must return by value....
>
> >>> Your _MEMBER_SET macro doesn't seem to fit the generated code that you
> show. I would think that
> >>>  _MEMBER_SET(name, name, const Glib::ustring&, gchar*)
>
> from https://github.com/GNOME/glibmm/blob/master/tools/m4/member.m4
> My understanding that the generated type will be const T& if T is provided
> to the macros.
>
> dnl Creates accessors for simple types:
>
> define(`_MEMBER_SET',`dnl
>
> ifelse(`$5',`deprecated',`_DEPRECATE_IFDEF_START ')dnl
>
> void set_$1(const $3`'& value);
>
> ifelse(`$5',`deprecated',`_DEPRECATE_IFDEF_END ')dnl
>
> _PUSH(SECTION_CC)
>
> ifelse(`$5',`deprecated',`_DEPRECATE_IFDEF_START ')dnl
>
> void __CPPNAME__::set_$1(const $3`'& value)
>
> {
>
> gobj()->$2 = _CONVERT($3,$4,`value');
>
> }
>
> ifelse(`$5',`deprecated',`_DEPRECATE_IFDEF_END ')dnl
>
>
> _POP()')
>
>
>
>
> Sorry, I was wrong. _MEMBER_SET(name, name, Glib::ustring, gchar*)
> does generate the code you showed.
>
> >> would generate that code. In this case a reference is OK, but it looks
> like the generated code can cause a memory leak. Who owns the duplicated
> string? Who deallocates it? What if gobj()->name contains a pointer to a
> string when set_name() is called?
>
>
> Basically once again, return by value. What would be the correct wrap for
> the simple struct? Wrap struct and manually wrap set/get method?
>
> I will investigate how private members are stored and how they related to
> the original C struct. Thanks
>
> In Glib::OptionEntry, _MEMBER_SET is not used for strings. Those methods
> are hand-coded to avoid a memory leak. Example:
>
> void OptionEntry::set_long_name(const Glib::ustring& value)
> {
>   if (gobject_->long_name)
>   {
>     g_free((gchar*)(gobject_->long_name));
>     gobject_->long_name = nullptr;
>   }
>
>   gobj()->long_name = (value).c_str() ? g_strdup((value).c_str()) :
> nullptr;
> }
>
>
> Don't ask me why value.c_str() is tested for nullptr. I don't understand.
> I don't think it can ever be a nullptr. And even if it is, g_strdup() can
> handle that.
>
>
>
> -Pavlo Solntsev
>
>
>
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