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Re: confusion about string.erase( --string.end() )

From: Marc Glisse <marc dot glisse at inria dot fr>
To: Pawel Sikora <pluto at agmk dot net>
Cc: gcc-help at gcc dot gnu dot org
Date: Tue, 22 Nov 2011 18:05:33 +0100 (CET)
Subject: Re: confusion about string.erase( --string.end() )
References: <8433837.L6u1V86xfQ@pawels>
Reply-to: gcc-help at gcc dot gnu dot org

On Tue, 22 Nov 2011, Pawel Sikora wrote:

Hi,

afaics the gcc-4.6 accepts following code:
#include <string>
int main()
{
       std::string line( "blabla" );
       line.erase( --line.end() );
}
but other compilers reject such code:
msvc8  : error C2105: '--' needs l-value
comeau : error: expression must be a modifiable lvalue
is it a bug in g++?

Hello,

your code is wrong. Libraries that use pointers as iterators will fail. Libraries that use classes are likely to work. There is nothing wrong with the fact that libstdc++ accepts this code.

When references on member functions are implemented, it would be possible to reject this code, but I am not sure we want to.

--
Marc Glisse

References:
- confusion about string.erase( --string.end() )
  - From: Pawel Sikora

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