The class transfer_at_least is a completion condition that is used to specify that a read or write operation should continue until a minimum number of bytes has been transferred, or until an error occurs.
namespace std { namespace experimental { namespace net { inline namespace v1 { class transfer_at_least { public: explicit transfer_at_least(size_t m); size_t operator()(const error_code& ec, size_t n) const; private: size_t minimum_; // exposition only }; } // inline namespace v1 } // namespace net } // namespace experimental } // namespace std
The class transfer_at_least satisfies the CompletionCondition ([buffer.stream.reqmts.completioncondition]) requirements.
explicit transfer_at_least(size_t m);
Postconditions: minimum_ == m.
size_t operator()(const error_code& ec, size_t n) const;
Returns: If !ec && n < minimum_, an unspecified non-zero value. Otherwise 0.