Updates files in the working tree to match the content of the index.
@param repo repository into which to check out (must be non-bare)
@param index index to be checked out (or null to use repository index)
@param opts specifies checkout options (may be null)
@return 0 on success, non-zero return value from notify_cb, or error
code < 0 (use git_error_last for error details)
Updates files in the working tree to match the content of the index.
@param repo repository into which to check out (must be non-bare) @param index index to be checked out (or null to use repository index) @param opts specifies checkout options (may be null) @return 0 on success, non-zero return value from notify_cb, or error code < 0 (use git_error_last for error details)