Casting away constness

[Martin Magnusson]

I have a typedef which looks like this:

typedef std::list< const S* const > seq_type;

I also have a class with a private field:

seq_type m_Sequence;

When calling the following method

M::AddSequence( seq_type seq )
{
m_Sequence.insert( m_Sequence.begin(),
seq.begin(),
seq.end() );
}

which is supposed to prepend the list "seq" to "m_Sequence" gcc tells me
that:

/usr/include/c++/3.2/bits/stl_construct.h:78: static_cast from type
`const S* const*' to type `void*' casts away constness

Why is that?

/ martin

[tom_usenet]

On Mon, 17 Nov 2003 11:26:34 +0100, Martin Magnusson
<lo*******@frustratedhousewives.zzn.com> wrote:

I have a typedef which looks like this:

typedef std::list< const S* const > seq_type;
The above is illegal - the elements of a list must be assignable. So:

typedef std::list< const S* > seq_type;

would be allowed. Some implementations might allow the former, but it
isn't standard or portable.

I also have a class with a private field:

seq_type m_Sequence;

When calling the following method

M::AddSequence( seq_type seq )
{
m_Sequence.insert( m_Sequence.begin(),
seq.begin(),
seq.end() );
}

which is supposed to prepend the list "seq" to "m_Sequence" gcc tells me
that:

/usr/include/c++/3.2/bits/stl_construct.h:78: static_cast from type
`const S* const*' to type `void*' casts away constness

Why is that?

I suspect for the reason I listed above.

Tom