From 93fc1aee4125b6d7afc19deb7d90b51ec9d5259f Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Sun, 4 Apr 2021 21:39:00 +0100
Subject: [PATCH] Add Gmpq::is_zero()

---
 Number_types/include/CGAL/GMP/Gmpq_type.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Number_types/include/CGAL/GMP/Gmpq_type.h b/Number_types/include/CGAL/GMP/Gmpq_type.h
index 451d2b00cdd..472fece35c1 100644
--- a/Number_types/include/CGAL/GMP/Gmpq_type.h
+++ b/Number_types/include/CGAL/GMP/Gmpq_type.h
@@ -228,6 +228,12 @@ public:
   double to_double() const noexcept;
   Sign sign() const noexcept;
 
+  bool is_zero() const
+  {
+    const __mpz_struct* zn = mpq_numref(mpq());
+    return mpn_zero_p(zn->_mp_d, zn->_mp_size);
+  }
+
   const mpq_t & mpq() const noexcept { return Ptr()->mpQ; }
   mpq_t & mpq() noexcept { return ptr()->mpQ; }