# Unary C++ Sequence Methods

> The following unary C++ methods and operator take no arguments, perform the indicated operation on the object's sequence and return a result sequence of the same type; or, in the case of `match()`, takes a character string argument pattern and returns a Boolean result sequence.

> Sequence<T> abs() const; | Return the sequence of absolute values of the object's elements
> Sequence<T> -() const; | Return the sequence of the negative of the object's elements
> Sequence<mco_seq_bool> match(char const* pattern) const; | Match the elements of a sequence of characters with the specified pattern and return a sequence of Boolean values

> ## Example

> Following is an example code snippet demonstrating unary operators :

>         {
>             ...
>             Sequence<float> high = quote.high_iterator();
>             Sequence<float> low = quote.low_iterator();
>             Sequence<float> diff;
>             Sequence<float> neg;
>             Sequence<float> abs;
>             ...
>             diff = high - low;

>             neg = -diff;

>             abs = abs(diff);

>             ...
>         }