I am having trouble getting my head around the memory ownership model for IUP's implementation of
IupSetAttribute() And the "string" related value functions like: IupSetStrAttribute() IupSetStrf() ... As I understand the documentation, IupSetAttribute() only stores references to strings but does NOT assume ownership of that memory. This means constant strings can be stored there, even local (stack-based) strings as long as they go out of scope AFTER the Ihandle associated with the attribute has been de-allocate/destroyed. This seems to imply that IUP makes absolutely no effort to ever "free" strings associated with an attribute when the Ihandle goes out of scope or is destroyed. Is this the correct understanding - that string values are never free()'ed? I am trying to understand how IupSetStrAttribute(), IupSetStrf() are different. The documentation states that these functions make a copy of the provided attribute value. Am I correct to assume that these copies are allocated from the heap? If they are allocated from the heap whose responsibility is it to free these values when the associated Ihandle has been deallocated/destroyed? If IUP frees these strings, how does it differentiate between heap allocated string values and constant ones that don't exist in the heap? Assuming I set all my attributes using IupSetStrAttribute() and friends is it the expectation the user is explicitly responsible for freeing the attribute values (e.g the library does not do it)? Is there a way to tell whether an attribute value resides on the heap or elsewhere? I can envision this scenario: /* Constant string - not allocated on the heap and no need to ever free. */ IupSetAttribute(hnd, "FOO", "bar"); /* Constant string "bar" is replaced by heap memory allocated for formatted "bar1" string */ IupSetStrf(hnd, "FOO", "bar%d", 1); /* Heap memory allocated for formatted "bar2" string - but did we just leak memory for "bar1"? */ IupSetStrf(hnd, "FOO", "bar%d", 2); These same questions (seem) to apply to the IupConfig() family of functions. Do they follow an identical memory ownership model as regular Ihandle attributes? Effectively who must manage the memory associated with value attributes: IUP or the user code that sets them (and possibly replaces one value with another). Thanks for any insights that can be offered . . .
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