diff --git a/glm/detail/qualifier.hpp b/glm/detail/qualifier.hpp
index 25ddf8ab..8c31c6dd 100644
--- a/glm/detail/qualifier.hpp
+++ b/glm/detail/qualifier.hpp
@@ -178,7 +178,7 @@ namespace detail
 	template<typename genType>
 	struct init_gentype<genType, GENTYPE_QUAT>
 	{
-		GLM_FUNC_QUALIFIER static genType identity()
+		GLM_FUNC_QUALIFIER GLM_CONSTEXPR static genType identity()
 		{
 			return genType(1, 0, 0, 0);
 		}
@@ -187,7 +187,7 @@ namespace detail
 	template<typename genType>
 	struct init_gentype<genType, GENTYPE_MAT>
 	{
-		GLM_FUNC_QUALIFIER static genType identity()
+		GLM_FUNC_QUALIFIER GLM_CONSTEXPR static genType identity()
 		{
 			return genType(1);
 		}
diff --git a/glm/detail/setup.hpp b/glm/detail/setup.hpp
index 380b63b7..da130b63 100644
--- a/glm/detail/setup.hpp
+++ b/glm/detail/setup.hpp
@@ -533,9 +533,11 @@ namespace glm
 }//namespace glm
 
 ///////////////////////////////////////////////////////////////////////////////////
-// countof
+// constexpr
 
 #if GLM_HAS_CONSTEXPR
+#	define GLM_USE_CONSTEXP GLM_ENABLE
+
 	namespace glm
 	{
 		template<typename T, std::size_t N>
@@ -546,8 +548,12 @@ namespace glm
 	}//namespace glm
 #	define GLM_COUNTOF(arr) glm::countof(arr)
 #elif defined(_MSC_VER)
+#	define GLM_USE_CONSTEXP GLM_DISABLE
+
 #	define GLM_COUNTOF(arr) _countof(arr)
 #else
+#	define GLM_USE_CONSTEXP GLM_DISABLE
+
 #	define GLM_COUNTOF(arr) sizeof(arr) / sizeof(arr[0])
 #endif
 
diff --git a/glm/gtc/matrix_transform.hpp b/glm/gtc/matrix_transform.hpp
index 4d3b8c83..cc94f634 100644
--- a/glm/gtc/matrix_transform.hpp
+++ b/glm/gtc/matrix_transform.hpp
@@ -38,7 +38,7 @@ namespace glm
 
 	/// Builds an identity matrix.
 	template<typename genType>
-	GLM_FUNC_DECL genType identity();
+	GLM_FUNC_DECL GLM_CONSTEXPR genType identity();
 
 	/// Builds a translation 4 * 4 matrix created from a vector of 3 components.
 	///
diff --git a/glm/gtc/matrix_transform.inl b/glm/gtc/matrix_transform.inl
index 7d0982d6..72349e04 100644
--- a/glm/gtc/matrix_transform.inl
+++ b/glm/gtc/matrix_transform.inl
@@ -8,7 +8,7 @@
 namespace glm
 {
 	template<typename genType>
-	GLM_FUNC_QUALIFIER genType identity()
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR genType identity()
 	{
 		return detail::init_gentype<genType, detail::genTypeTrait<genType>::GENTYPE>::identity();
 	}
diff --git a/glm/gtc/quaternion.hpp b/glm/gtc/quaternion.hpp
index 240f3d12..2d65dea0 100644
--- a/glm/gtc/quaternion.hpp
+++ b/glm/gtc/quaternion.hpp
@@ -57,7 +57,7 @@ namespace glm
 		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 4;}
 
 		GLM_FUNC_DECL T & operator[](length_type i);
-		GLM_FUNC_DECL T const& operator[](length_type i) const;
+		GLM_FUNC_DECL GLM_CONSTEXPR T const& operator[](length_type i) const;
 
 		// -- Implicit basic constructors --
 
@@ -156,14 +156,14 @@ namespace glm
 	// -- Boolean operators --
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_DECL bool operator==(tquat<T, Q> const& q1, tquat<T, Q> const& q2);
+	GLM_FUNC_DECL GLM_CONSTEXPR bool operator==(tquat<T, Q> const& q1, tquat<T, Q> const& q2);
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_DECL bool operator!=(tquat<T, Q> const& q1, tquat<T, Q> const& q2);
+	GLM_FUNC_DECL GLM_CONSTEXPR bool operator!=(tquat<T, Q> const& q1, tquat<T, Q> const& q2);
 
 	/// Builds an identity quaternion.
 	template<typename genType>
-	GLM_FUNC_DECL genType identity();
+	GLM_FUNC_DECL GLM_CONSTEXPR genType identity();
 
 	/// Returns the length of the quaternion.
 	///
diff --git a/glm/gtc/quaternion.inl b/glm/gtc/quaternion.inl
index f235e173..d7b01a09 100644
--- a/glm/gtc/quaternion.inl
+++ b/glm/gtc/quaternion.inl
@@ -82,7 +82,7 @@ namespace detail
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER T const& tquat<T, Q>::operator[](typename tquat<T, Q>::length_type i) const
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR T const& tquat<T, Q>::operator[](typename tquat<T, Q>::length_type i) const
 	{
 		assert(i >= 0 && i < this->length());
 		return (&x)[i];
@@ -377,15 +377,15 @@ namespace detail
 	// -- Boolean operators --
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER bool operator==(tquat<T, Q> const& q1, tquat<T, Q> const& q2)
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR bool operator==(tquat<T, Q> const& q1, tquat<T, Q> const& q2)
 	{
-		return all(epsilonEqual(q1, q2, epsilon<T>()));
+		return q1.x == q2.x && q1.y == q2.y && q1.z == q2.z && q1.w == q2.w;
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER bool operator!=(tquat<T, Q> const& q1, tquat<T, Q> const& q2)
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR bool operator!=(tquat<T, Q> const& q1, tquat<T, Q> const& q2)
 	{
-		return any(epsilonNotEqual(q1, q2, epsilon<T>()));
+		return q1.x != q2.x || q1.y != q2.y || q1.z != q2.z || q1.w != q2.w;
 	}
 
 	// -- Operations --
diff --git a/test/core/CMakeLists.txt b/test/core/CMakeLists.txt
index 12d76bf3..1990cff1 100644
--- a/test/core/CMakeLists.txt
+++ b/test/core/CMakeLists.txt
@@ -1,3 +1,4 @@
+glmCreateTestGTC(core_cpp_constexpr)
 glmCreateTestGTC(core_cpp_defaulted_ctor)
 glmCreateTestGTC(core_force_aligned_gentypes)
 glmCreateTestGTC(core_force_ctor_init)
diff --git a/test/core/core_cpp_constexpr.cpp b/test/core/core_cpp_constexpr.cpp
new file mode 100644
index 00000000..c8d07e6c
--- /dev/null
+++ b/test/core/core_cpp_constexpr.cpp
@@ -0,0 +1,278 @@
+#include <glm/glm.hpp>
+
+#if GLM_USE_CONSTEXP == GLM_ENABLE
+
+#include <glm/gtc/constants.hpp>
+#include <glm/gtc/quaternion.hpp>
+#include <glm/ext/vector_relational.hpp>
+#include <glm/ext/vec1.hpp>
+
+static int test_vec1()
+{
+	int Error = 0;
+
+	{
+		constexpr glm::ivec1 O(glm::ivec1(1));
+		static_assert(glm::ivec1(1) == O, "GLM: Failed constexpr");
+
+		constexpr glm::ivec1 P(1);
+		static_assert(glm::ivec1(1) == P, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec1 L(glm::ivec2(1, 2));
+		static_assert(glm::ivec1(1) == L, "GLM: Failed constexpr");
+
+		constexpr glm::ivec1 M(glm::ivec3(1, 2, 3));
+		static_assert(glm::ivec1(1) == M, "GLM: Failed constexpr");
+
+		constexpr glm::ivec1 N(glm::ivec4(1, 2, 3, 4));
+		static_assert(glm::ivec1(1) == N, "GLM: Failed constexpr");
+	}
+
+	{
+		static_assert(glm::vec1(1.0f).x > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec1::length() == 1, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::bvec1 A1(true);
+		constexpr glm::bvec1 A2(true);
+		constexpr glm::bvec1 B1(false);
+		constexpr glm::bvec1 B2(false);
+		static_assert(A1 == A2 && B1 == B2, "GLM: Failed constexpr");
+		static_assert(A1 == A2 || B1 == B2, "GLM: Failed constexpr");
+	}
+
+	return Error;
+}
+
+static int test_vec2()
+{
+	int Error = 0;
+
+	{
+		constexpr glm::ivec2 O(glm::ivec1(1));
+		static_assert(glm::ivec2(1) == O, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 A(1);
+		static_assert(glm::ivec2(1) == A, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec2 F(glm::ivec1(1), glm::ivec1(2));
+		static_assert(glm::ivec2(1, 2) == F, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 G(1, glm::ivec1(2));
+		static_assert(glm::ivec2(1, 2) == G, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 H(glm::ivec1(1), 2);
+		static_assert(glm::ivec2(1, 2) == H, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 I(1, 2);
+		static_assert(glm::ivec2(1, 2) == I, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec2 L(glm::ivec2(1, 2));
+		static_assert(glm::ivec2(1, 2) == L, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 M(glm::ivec3(1, 2, 3));
+		static_assert(glm::ivec2(1, 2) == M, "GLM: Failed constexpr");
+
+		constexpr glm::ivec2 N(glm::ivec4(1, 2, 3, 4));
+		static_assert(glm::ivec2(1, 2) == N, "GLM: Failed constexpr");
+	}
+
+	{
+		static_assert(glm::vec2(1.0f).x > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec2(1.0f, -1.0f).x > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec2(1.0f, -1.0f).y < 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec2::length() == 2, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::bvec2 A1(true);
+		constexpr glm::bvec2 A2(true);
+		constexpr glm::bvec2 B1(false);
+		constexpr glm::bvec2 B2(false);
+		static_assert(A1 == A2 && B1 == B2, "GLM: Failed constexpr");
+		static_assert(A1 == A2 || B1 == B2, "GLM: Failed constexpr");
+	}
+
+	return Error;
+}
+
+static int test_vec3()
+{
+	int Error = 0;
+
+	{
+		constexpr glm::ivec3 O(glm::ivec1(1));
+		static_assert(glm::ivec3(1) == O, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 A(1);
+		static_assert(glm::ivec3(1) == A, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec3 B(glm::ivec2(1, 2), 3);
+		static_assert(glm::ivec3(1, 2, 3) == B, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 C(1, glm::ivec2(2, 3));
+		static_assert(glm::ivec3(1, 2, 3) == C, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 D(glm::ivec1(1), glm::ivec2(2, 3));
+		static_assert(glm::ivec3(1, 2, 3) == D, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 E(glm::ivec2(1, 2), glm::ivec1(3));
+		static_assert(glm::ivec3(1, 2, 3) == E, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec3 F(glm::ivec1(1), glm::ivec1(2), glm::ivec1(3));
+		static_assert(glm::ivec3(1, 2, 3) == F, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 G(1, glm::ivec1(2), glm::ivec1(3));
+		static_assert(glm::ivec3(1, 2, 3) == G, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 H(glm::ivec1(1), 2, glm::ivec1(3));
+		static_assert(glm::ivec3(1, 2, 3) == H, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 I(1, 2, glm::ivec1(3));
+		static_assert(glm::ivec3(1, 2, 3) == I, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 J(glm::ivec1(1), glm::ivec1(2), 3);
+		static_assert(glm::ivec3(1, 2, 3) == J, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 K(1, glm::ivec1(2), 3);
+		static_assert(glm::ivec3(1, 2, 3) == K, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 L(glm::ivec1(1), 2, 3);
+		static_assert(glm::ivec3(1, 2, 3) == L, "GLM: Failed constexpr");
+
+		constexpr glm::ivec3 M(1, 2, 3);
+		static_assert(glm::ivec3(1, 2, 3) == M, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec3 N(glm::ivec4(1, 2, 3, 4));
+		static_assert(glm::ivec3(1, 2, 3) == N, "GLM: Failed constexpr");
+	}
+
+	{
+		static_assert(glm::vec3(1.0f).x > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec3(1.0f, -1.0f, -1.0f).x > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec3(1.0f, -1.0f, -1.0f).y < 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::vec3::length() == 3, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::bvec3 A1(true);
+		constexpr glm::bvec3 A2(true);
+		constexpr glm::bvec3 B1(false);
+		constexpr glm::bvec3 B2(false);
+		static_assert(A1 == A2 && B1 == B2, "GLM: Failed constexpr");
+		static_assert(A1 == A2 || B1 == B2, "GLM: Failed constexpr");
+	}
+
+	return Error;
+}
+
+static int test_vec4()
+{
+	int Error = 0;
+
+	{
+		constexpr glm::ivec4 O(glm::ivec4(1));
+		static_assert(glm::ivec4(1) == O, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 A(1);
+		static_assert(glm::ivec4(1) == A, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 N(glm::ivec4(1, 2, 3, 4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == N, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::ivec4 A(glm::ivec3(1, 2, 3), 4);
+		static_assert(glm::ivec4(1, 2, 3, 4) == A, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 B(glm::ivec2(1, 2), glm::ivec2(3, 4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == B, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 C(1, glm::ivec3(2, 3, 4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == C, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 D(glm::ivec1(1), glm::ivec2(2, 3), glm::ivec1(4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == D, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 E(glm::ivec2(1, 2), glm::ivec1(3), glm::ivec1(4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == E, "GLM: Failed constexpr");
+
+		constexpr glm::ivec4 F(glm::ivec1(1), glm::ivec1(2), glm::ivec2(3, 4));
+		static_assert(glm::ivec4(1, 2, 3, 4) == F, "GLM: Failed constexpr");
+	}
+
+	{
+		static_assert(glm::ivec4(1).x > 0, "GLM: Failed constexpr");
+		static_assert(glm::ivec4(1.0f, -1.0f, -1.0f, 1.0f).x > 0, "GLM: Failed constexpr");
+		static_assert(glm::ivec4(1.0f, -1.0f, -1.0f, 1.0f).y < 0, "GLM: Failed constexpr");
+		static_assert(glm::ivec4::length() == 4, "GLM: Failed constexpr");
+	}
+
+	{
+		constexpr glm::bvec4 A1(true);
+		constexpr glm::bvec4 A2(true);
+		constexpr glm::bvec4 B1(false);
+		constexpr glm::bvec4 B2(false);
+		static_assert(A1 == A2 && B1 == B2, "GLM: Failed constexpr");
+		static_assert(A1 == A2 || B1 == B2, "GLM: Failed constexpr");
+	}
+
+	return Error;
+}
+
+static int test_quat()
+{
+	int Error = 0;
+
+	{
+		static_assert(glm::quat::length() == 4, "GLM: Failed constexpr");
+		static_assert(glm::quat(1.0f, glm::vec3(0.0f)).w > 0.0f, "GLM: Failed constexpr");
+		static_assert(glm::quat(1.0f, 0.0f, 0.0f, 0.0f).w > 0.0f, "GLM: Failed constexpr");
+
+		glm::quat constexpr Q = glm::identity<glm::quat>();
+		static_assert(Q.x - glm::quat(1.0f, glm::vec3(0.0f)).x <= glm::epsilon<float>(), "GLM: Failed constexpr");
+	}
+
+	return Error;
+}
+
+static int test_mat2x2()
+{
+	int Error = 0;
+
+	static_assert(glm::mat2x2::length() == 2, "GLM: Failed constexpr");
+
+	return Error;
+}
+
+#endif//GLM_USE_CONSTEXP == GLM_ENABLE
+
+int main()
+{
+	int Error = 0;
+
+#	if GLM_USE_CONSTEXP == GLM_ENABLE
+		Error += test_vec1();
+		Error += test_vec2();
+		Error += test_vec3();
+		Error += test_vec4();
+		Error += test_quat();
+		Error += test_mat2x2();
+#	endif//GLM_USE_CONSTEXP == GLM_ENABLE
+
+	return Error;
+}
+