From daf02ba762c5469ba07165482f31d126a8442b08 Mon Sep 17 00:00:00 2001
From: Marshall Vielmetti <mvielmetti@outlook.com>
Date: Sun, 26 Jan 2025 16:28:44 -0600
Subject: [PATCH] added to tangent base and evalIsApprox

---
 include/manif/impl/tangent_base.h | 16 ++++++++++++++++
 test/common_tester.h              |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/include/manif/impl/tangent_base.h b/include/manif/impl/tangent_base.h
index 6d5178a4..56c37eb5 100644
--- a/include/manif/impl/tangent_base.h
+++ b/include/manif/impl/tangent_base.h
@@ -946,6 +946,22 @@ bool operator ==(
   return t.isApprox(v);
 }
 
+template <typename _Derived, typename _DerivedOther>
+bool operator !=(
+    const TangentBase<_Derived>& ta,
+    const TangentBase<_DerivedOther>& tb)
+{
+  return !(ta == tb);
+}
+
+template <typename _Derived, typename _EigenDerived>
+bool operator !=(
+    const TangentBase<_Derived>& t,
+    const Eigen::MatrixBase<_EigenDerived>& v)
+{
+  return !(t == v);
+}
+
 // Utils
 
 template <typename _Stream, typename _Derived>
diff --git a/test/common_tester.h b/test/common_tester.h
index bc7ce126..592e8594 100644
--- a/test/common_tester.h
+++ b/test/common_tester.h
@@ -522,6 +522,7 @@ class CommonTester
     EXPECT_TRUE(LieGroup::Identity().isApprox(LieGroup::Identity(), tol_));
 
     EXPECT_TRUE(LieGroup::Identity() == LieGroup::Identity());
+    EXPECT_FALSE(LieGroup::Identity() != LieGroup::Identity());
 
     EXPECT_TRUE(getState().isApprox(getState(), tol_));
     EXPECT_FALSE(getState().isApprox(LieGroup::Random(), tol_));
@@ -529,12 +530,14 @@ class CommonTester
     // cppcheck-suppress duplicateExpression
     EXPECT_TRUE(getState() == getState());
     EXPECT_FALSE(getState() == LieGroup::Random());
+    EXPECT_TRUE(getState() != LieGroup::Random());
 
     // Tangent
 
     EXPECT_TRUE(Tangent::Zero().isApprox(Tangent::Zero(), tol_));
 
     EXPECT_TRUE(Tangent::Zero() == Tangent::Zero());
+    EXPECT_FALSE(Tangent::Zero() != Tangent::Zero());
 
     EXPECT_TRUE(getDelta().isApprox(getDelta(), tol_));
     EXPECT_FALSE(getDelta().isApprox(Tangent::Random(), tol_));
@@ -542,6 +545,7 @@ class CommonTester
     // cppcheck-suppress duplicateExpression
     EXPECT_TRUE(getDelta() == getDelta());
     EXPECT_FALSE(getDelta() == Tangent::Random());
+    EXPECT_TRUE(getDelta() != Tangent::Random());
   }
 
   void evalUnaryMinus()