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From: greghunt@zeta.org.au
Subject: Is the exception behaviour of iostreams Implementation defined?
Date: 1995/06/09
Message-ID: <3r85ii$a69@godzilla.zeta.org.au>#1/1
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organization: Kralizec Dialup Unix Sydney, +61-2-837-1183 V.32bis
reply-to: greghunt@zeta.org.au
newsgroups: comp.std.c++

The draft at Table 72 (27-16) shows that ios_base construction sets (in some
way) exceptions() to goodbit.  I assume that this means that no setstate() 
operation on the base class will throw and exception.

At 27.4.4.3 iostate exceptions() const; indicates which iostates may cause
exceptions to be thrown.

Elsewhere (27.6.1.2.2 para 2 for example) it says that setstate(failbit) may
throw an ios_base::failure exception.  Again at 27.6.1.3 para 2 basic_istream
may call setstate() at eof and thus possibly throw an exception.

Is the mapping between states and exceptions implementation defined?  Where
is it set?  Personally I am not fond of file system behaviour that treats
eof as an exception but I can't see how I can know in advance what the
exception behaviour is going to be.  

Can anyone clarify this for me?  Have I missed something?