Construct a basic_file
without opening it.
template< typename ExecutionContext> basic_file( ExecutionContext & context, typename constraint< is_convertible< ExecutionContext &, execution_context & >::value, defaulted_constraint >::type = defaulted_constraint());
This constructor initialises a file without opening it.
An execution context which provides the I/O executor that the file will use, by default, to dispatch handlers for any asynchronous operations performed on the file.