14.5 Input and Output

The complex arithmetic library provides default extractors and inserters for complex numbers, as shown in the following example:

ostream& operator<<(ostream&, const complex&); //inserter
istream& operator>>(istream&, complex&); //extractor

For basic information on extractors and inserters, see 13.2 Basic Structure of iostream Interaction and 13.3.1 Output Using iostream.

For input, the complex extractor >> extracts a pair of numbers (surrounded by parentheses and separated by a comma) from the input stream and reads them into a complex object. The first number is taken as the value of the real part; the second as the value of the imaginary part. For example, given the declaration and input statement:

complex x;
cin >> x;

and the input (3.45, 5), the value of x is equivalent to 3.45 + 5.0i. The reverse is true for inserters. Given complex x(3.45, 5), cout<<x prints (3.45, 5).

The input usually consists of a pair of numbers in parentheses separated by a comma; white space is optional. If you provide a single number, with or without parentheses and white space, the extractor sets the imaginary part of the number to zero. Do not include the symbol i in the input text.

The inserter inserts the values of the real and imaginary parts enclosed in parentheses and separated by a comma. It does not include the symbol i. The two values are treated as doubles.