# mongoc_write_concern_append()¶

## Synopsis¶

bool
mongoc_write_concern_append (mongoc_write_concern_t *write_concern,
bson_t *command);


## Description¶

This function appends a write concern to command options. It is useful for appending a write concern to command options before passing them to mongoc_client_write_command_with_opts() or a related function that takes an options document.

## Returns¶

Returns true on success. If any arguments are invalid, returns false and logs an error.

## Example¶

See the example code for mongoc_client_write_command_with_opts().