== cobalt/io/read.hpp

The `write` and `write_at` write the full buffer to a stream.

[source,cpp]
----

struct write_all final : op<system::error_code, std::size_t>
{
  read_op step;
  write_all(read_op op);
};
write_all write(stream & str, const_buffer_sequence buffer);


struct write_all_at final : op<system::error_code, std::size_t>
{
  write_at_op step;
  write_all_at(write op);
};
write_all_at write_at(stream & str, std::uint64_t offset, const_buffer_sequence buffer);
----