## CGAL::Is_y_monotone_2<Traits>

### Definition

Function object class that tests whether a sequence of points represents a y-monotone polygon or not.

#include <CGAL/polygon_function_objects.h>

### Is Model for the Concept

PolygonIsValid

### Creation

Is_y_monotone_2<Traits> f ( Traits t);
| Traits is a model of the concept IsYMonotoneTraits_2

### Operations

template<class InputIterator>
bool | f ( InputIterator first, InputIterator beyond)
|  | returns true iff the points of type Traits::Point_2 in the range [first,beyond) define a y-monotone polygon.

### See Also

CGAL::convex_partition_is_valid_2
CGAL::Partition_is_valid_traits_2<Traits, PolygonIsValid>

### Implementation

This test requires O(n) time for a polygon with n vertices.