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I'm writing some C code where I want to have a NULL-terminated GPtrArray containing static strings. Typically, I would use g_ptr_array_new_null_terminated () to construct a NULL-terminated GPtrArray, but it requires me to specify a function that frees the elements upon destruction—something you don't want with statically allocated strings, of course. However, I don't find any constructor that gives you a NULL-terminated array that doesn't require providing an element free function: both g_ptr_array_new_from_null_terminated_array () and g_ptr_array_new_take_null_terminated () require an element_free_func argument that cannot be set to NULL according to the documentation.

One option would of course be to just make a no-op function that fits the GDestroyNotify function signature, but it doesn't feel particularly elegant. Is there a better way of achieving this?

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    I think the no-op function is the intended solution. Elegance be damned! Commented yesterday

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It's not documented, but it skips freeing when element_free_func is NULL. From the glib source code:

  if (rarray->element_free_func != NULL)
    {
      for (i = index_; i < index_ + length; i++)
        rarray->element_free_func (rarray->pdata[i]);
    }

But if you want to stick to documented features, I think the no-op function is the expected solution.

I think this is intended, so perhaps this should be considered a documentation bug and you could submit a bug report about it.

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I don't see any check for a NULL free function in this part of the code that allocates a new array: gitlab.gnome.org/GNOME/glib/-/blob/main/glib/garray.c#L1139
It doesn't check when creating, it checks when freeing.
The issue would be a check in the creation for a non-NULL free function causing the creation to fail.
Right. If it actively rejected this, it would be a problem. But it doesn't, it just saves whatever you provide in the element_free_func member variable, and uses it safely later.
element_free_func can be null. From Andrew's link, looking at (e.g.) the g_ptr_array_new_take function (amongst others), we have a comment: gitlab.gnome.org/GNOME/glib/-/blob/main/glib/garray.c#L1190 which is: @element_free_func: (nullable): a function to free elements on @array destruction Note the "(nullable)". Although this looks like a doxygen-like comment syntax, it doesn't (seem to) go to the docs pages, so it's "semi-documented" ;-)
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I don't find any constructor that gives you a NULL-terminated array that doesn't require providing an element free function

Indeed, of the 8 (!) constructor functions in total for objects of this type, only g_ptr_array_new() does not take a pointer to a free function as an argument, and that function does not produce an array of the null-terminated flavor.

However, the docs do not specify the implications of providing a null pointer for the freeing function, and in practice, g_ptr_array_new() behaves as if you had passed such a null pointer. I don't necessarily think it's safe to rely on that, but it looks like you could get away with it for now. I would recommend documenting such an assumption if you make it.

One option would of course be to just make a no-op function that fits the GDestroyNotify function signature, but it doesn't feel particularly elegant.

I don't see why that seems inelegant to you. It seems natural to me.

Is there a better way of achieving this?

The way you propose seems fine to me, and it is the safest, most forward-looking option. However, if you can't bear to do that then it appears that using g_ptr_array_new_null_terminated() and passing NULL as the element freeing function probably would work too.

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