\begin{ccRefFunction}{is_square} \ccDefinition An ring element $x$ is said to be a square iff there exists a ring element $y$ such that $x= y*y$. In case the ring is a \ccc{UniqueFactorizationDomain}, $y$ is uniquely defined up to multiplication by units. \\ The function \ccRefName\ is available if \ccc{Algebraic_structure_traits::Is_square} is not the \ccc{CGAL::Null_functor}. \ccInclude{CGAL/number_utils.h} \ccFunction{template result_type is_square(const NT& x);}{ The \ccc{result_type} is convertible to \ccc{bool}. } \ccFunction{template result_type is_square(const NT& x, NT& y);}{ The \ccc{result_type} is convertible to \ccc{bool}. } \ccSeeAlso \ccRefConceptPage{UniqueFactorizationDomain}\\ \ccRefConceptPage{AlgebraicStructureTraits::IsSquare}\\ \end{ccRefFunction}