Constant buffer sequence requirements

A constant buffer sequence represents a set of memory regions that may be used as input to an operation, such as the send operation of a socket.

A type X meets the ConstBufferSequence requirements if it satisfies the requirements of Destructible (C++Std [destructible]) and CopyConstructible (C++Std [copyconstructible]), as well as the additional requirements listed below.

In the table below, x denotes a (possibly const) value of type X, and u denotes an identifier.

Table 8. ConstBufferSequence requirements

expression	return type	assertion/note pre/post-condition
`asio::buffer_sequence_begin(x)` `asio::buffer_sequence_end(x)`	An iterator type meeting the requirements for bidirectional iterators (C++Std [bidirectional.iterators]) whose value type is convertible to `const_buffer`.
X u(x);		post: equal( asio::buffer_sequence_begin(x), asio::buffer_sequence_end(x), asio::buffer_sequence_begin(u), asio::buffer_sequence_end(u), [](const const_buffer& b1, const const_buffer& b2) { return b1.data() == b2.data() && b1.size() == b2.size(); })

expression

return type

assertion/note
pre/post-condition

asio::buffer_sequence_begin(x)
asio::buffer_sequence_end(x)

An iterator type meeting the requirements for bidirectional iterators (C++Std [bidirectional.iterators]) whose value type is convertible to const_buffer.

X u(x);

post:

equal(
  asio::buffer_sequence_begin(x),
  asio::buffer_sequence_end(x),
  asio::buffer_sequence_begin(u),
  asio::buffer_sequence_end(u),
  [](const const_buffer& b1,
     const const_buffer& b2)
   {
     return b1.data() == b2.data()
         && b1.size() == b2.size();
   })