function checkComment( comment, rType, flg ) {
	var matches;
	var str;
	var val;

	str = comment.value;
	matches = str.match( RE_ANNOTATION );
	if ( matches ) {
		val = matches[ 1 ];
		if ( flg ) {
			if ( RE_NUMBER.test( val ) && !contains( val, '.' ) ) {
				return '`//'+str+'` should be `//'+createReplacement( str, flg )+'` (return annotations for values of type `'+rType+'` must always include a decimal point)';
			}
		}
		else if ( contains( val, '.0' ) ) {
			return '`//'+str+'` should be `//'+createReplacement( str, flg )+'` (return annotations for values of type `'+rType+'` must NOT include a decimal point)';
		}
	}
	return null;
}
Checks whether a comment is a return annotation and, if so, whether it only includes decimal points for real-valued return values.

@private
@param {string} comment - comment to examine
@param {string} rType - JSDoc return type
@param {boolean} flg - boolean indicating whether annotation must include decimal point
@returns {(string|null)} error message or null