!standard B.3.1    (24)                               99-08-31  AI95-00140/02
!class binding interpretation 96-05-07
!status Corrigendum 2000 99-05-27
!status WG9 approved 96-12-07
!status ARG approved 7-0-1  96-06-17
!status work item 96-05-08
!status received 96-05-07
!priority Low
!difficulty Easy
!qualifier Omission
!subject Semantics of Interfaces.C.Strings.To_Char_Ptr when Nul_Check is False

!summary

If Nul_Check is False, Interfaces.C.Strings.To_Char_Ptr performs a
pointer conversion with no allocation of memory.

!question

B.3.1(23-24) says:

23  function To_Chars_Ptr (Item      : in char_array_access;
                           Nul_Check : in Boolean := False)
       return chars_ptr;

        24   If Item is null, then To_Chars_Ptr returns Null_Ptr.  Otherwise,
        if Nul_Check is True and Item.all does not contain nul, then the
        function propagates Terminator_Error; if Nul_Check is True and
        Item.all does contain nul, To_Chars_Ptr performs a pointer conversion
        with no allocation of memory.

This does not seem to cover the case where Nul_Check is False.

!recommendation

(See summary.)

!wording

Change B.3.1(24) to:

        24  If Item is null, then To_Chars_Ptr returns Null_Ptr.
        Otherwise, if Nul_Check is True and Item.all does not contain
        nul, then the function propagates Terminator_Error.  Otherwise,
        To_Chars_Ptr performs a pointer conversion with no allocation of
        memory.

Or, equivalently:

        24  If Nul_Check is True, Item is non-null, and Item.all does not
        contain nul, Terminator_Error is propagated.  Otherwise,
        To_Chars_Ptr performs a pointer conversion with no allocation of
        memory.

!discussion

(See summary.)

!corrigendum B.03.01(24)

@drepl
@xindent<If Item is @b<null>, then To_Chars_Ptr returns Null_Ptr.  Otherwise,
if Nul_Check is True and Item.@b<all> does not contain nul, then the
function propagates Terminator_Error; if Nul_Check is True and
Item.@b<all> does contain nul, To_Chars_Ptr performs a pointer conversion
with no allocation of memory.>
@dby
@xindent<If Item is @b<null>, then To_Chars_Ptr returns Null_Ptr.
Otherwise, if Nul_Check is True and Item.@b<all> does not contain
nul, then the function propagates Terminator_Error. Otherwise,
To_Chars_Ptr performs a pointer conversion with no allocation of memory.>

!ACATS test

A test case for Nul_Check => False should be added to the existing test of
this function (CXB3009).

!appendix

!section B.3.1(24)
!subject Semantics of Interfaces.C.Strings.To_Char_Ptr when Nul_Check is False
!reference RM95 B.3.1(24)
!from Pascal Leroy 96-04-29
!reference 96-5528.c Pascal Leroy 96-4-29>>
!discussion

The referenced paragraph describes the semantics of To_Char_Ptr as follows (I
am omitting the details to shows the logical structure):

"If Item is null ... Otherwise if Nul_Check is True and Item.all doesn't
contain nul ...; if Nul_Check is True and Item.all does contain nul ..."

This sentence doesn't appear to cover the case where Nul_Check is False.  Not
that the semantics is hard to guess, but it would be nice if it was explicitly
stated.

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