Section: 16.4.5.6 [replacement.functions], 17.6.3 [new.delete] Status: CD1 Submitter: Matt Austern Opened: 2003-04-24 Last modified: 2016-01-28
Priority: Not Prioritized
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Discussion:
The eight basic dynamic memory allocation functions (single-object and array versions of ::operator new and ::operator delete, in the ordinary and nothrow forms) are replaceable. A C++ program may provide an alternative definition for any of them, which will be used in preference to the implementation's definition.
Three different parts of the standard mention requirements on replacement functions: 16.4.5.6 [replacement.functions], 17.6.3.2 [new.delete.single] and 17.6.3.3 [new.delete.array], and 6.7.5.4 [basic.stc.auto].
None of these three places say whether a replacement function may
be declared inline. 17.6.3.2 [new.delete.single] paragraph 2 specifies a
signature for the replacement function, but that's not enough:
the inline specifier is not part of a function's signature.
One might also reason from 9.2.3 [dcl.fct.spec] paragraph 2, which
requires that "an inline function shall be defined in every
translation unit in which it is used," but this may not be quite
specific enough either. We should either explicitly allow or
explicitly forbid inline replacement memory allocation
functions.
Proposed resolution:
Add a new sentence to the end of 16.4.5.6 [replacement.functions] paragraph 3:
"The program's definitions shall not be specified as inline.
No diagnostic is required."
[Kona: added "no diagnostic is required"]
Rationale:
The fact that inline isn't mentioned appears to have been
nothing more than an oversight. Existing implementations do not
permit inline functions as replacement memory allocation functions.
Providing this functionality would be difficult in some cases, and is
believed to be of limited value.