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Boris Bralo · Guest

Hi all,

I've just red N1870
(http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1870.html )
section 2.5 ("Add set_buffer( T*, size_t ) to vector and basic_string")
and I like it since I'm working in the embedded and I need such
functionality.

1)
Maybe we should add the method to give ownership of the buffer too:

T* release_buffer()
Postcondition:
container.size()==0

2)
Custom allocator in std::vector will be a problem in both cases.
However, it can be solved by adding parameter to methods:

template <typename Allocator> set_buffer( T* b, size_t s, Allocator a);
Postcondition:
container.buffer()==b,
container.size()==s,
container.allocator()==a,

For release_buffer:

shared_array<T, DeleterAdapter release_buffer()
Postcondition:
container.buffer()==NULL,
container.size()==0,

DeleterAdapter is shared_array "deleter" that coresponds to container's
allocator, something like:

template <typename T, typename A>
struct DeleterAdapter
{
const A& m_a;
size_t m_size;
DeleterAdapter( const A& a, size_t s)
:m_a(a), m_size(s)
{
}

void operator()(T* p)
{
for(size_t i=0; i m_a.destroy(p+i);

m_a.deallocate(p, m_size);
}
}

Of course, there should be specializations for both allocator and
DeleteAdapter that'll handle most common case ( i.e array allocated with
array new) etc.

Boris

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thorsten.ottosen@dezide.c · Guest

Boris Bralo skrev: