Re: libstdc++/4458: std::ctype<char>::is doesn't call do_is as required by ISO 14882

[James Kanze <kanze@YAST_ASK.sourceware.cygnus.com>]

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The following reply was made to PR libstdc++/4458; it has been noted by GNATS.

From: James Kanze <kanze@YAST_ASK>
To: Martin Sebor <sebor@roguewave.com>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/4458: std::ctype<char>::is doesn't call do_is as required   by ISO 14882
Date: 14 Oct 2001 22:16:52 +0200

 Martin Sebor <sebor@roguewave.com> writes:
 
 |>  kanze@gabi-soft.de wrote:
 
 |>  > >Number:         4458
 |>  > >Category:       libstdc++
 |>  > >Synopsis:       std::ctype<char>::is doesn't call do_is as required by ISO 14882
 
 |>  It's not required to do so for efficiency (see 22.2.1.3.2, p5).
 
 §22.2.1.1.1/1: concerning std::ctype<>::is:
 
     Returns: do_is(m,c)
 
 Can't be any clearer than that.  The function do_is is required by the
 standard to be virtual, which means that the actual function called (and
 thus the actual semantics of the function is) depend on the dynamic type
 of the object.  This is, after all, the whole point behind defining the
 protected virtual functions -- any other interpretation, and having the
 protected interface makes sense.
 
 -- 
 James Kanze                                mailto:kanze@gabi-soft.de
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