Issue 162:  Portably getting the value of the bounds of a sequence                                                                                                                                                 (c_mapping-rtf)
Source:  (, )
Nature:  Uncategorized
Severity:  Medium
Summary: Summary: Section 14.11: It"s not clear how a portable application could know value of bound of sequence. It"s specified in PIDL but is not represented in generated C header

Resolution: add sentence
Revised Text: Add sentence to 

start the 3rd 

paragraph on 

p,1-14 June 99 

spec

The _maximum member for a bounded sequence should be set to the 

length of the bound when the sequence is allocated. Thereafter 

accessing the _maximum will return the value of the bound. Resetting the 

value of _maximum for a bounded sequence can result in unpredictable 

behavior.
Actions taken:
October 10, 1996: received issue
October 5, 2000: closed issue
Discussion: 
It not clear what a C language mapping could do to provide this 

information.  The C++ language mapping simply states that maximum() 

for a bounded sequence will always return the  bound, but they can make 

that happen via the class.  The C language could do likewise, accessing 

the _maximum parameter will return the sequence bound but, that would 

only be true if the application had not at some point changed the bound.
End of Annotations:=====

Issue 162: Portably getting the value of the bounds of a sequence
Summary: Section 14.11: It"s not clear how a portable application
could know
value of bound of sequence. It"s specified in PIDL but is not
represented in
generated C header

Discussion - It not clear what a C language mapping could do to
provide this
information.  The C++ language mapping simply states that maximum()
for a
bounded sequence will always return the  bound, but they can make that
happen via the class.  The C language could do likewise, accessing the
_maximum parameter will return the sequence bound but, that would only
be
true if the application had not at some point changed the bound.  In
the C
mapping I see no way to prevent it.  I propose we address the issue by
adding a sentence to the paragraph that addresses setting _length and
_maximum errors to state:  "The _maximum member for a bounded sequence
should be set to the length of the bound when the sequence is
allocated.
Thereafter accessing the _maximum will return the value of the bound.
Resetting the value of _maximum for a bounded sequence is an error
that can
result in unpredictable behavior."