diff --git a/Eigen/src/Core/Array.h b/Eigen/src/Core/Array.h
index b65285282..1242d1946 100644
--- a/Eigen/src/Core/Array.h
+++ b/Eigen/src/Core/Array.h
@@ -21,6 +21,10 @@ struct traits<Array<Scalar_, Rows_, Cols_, Options_, MaxRows_, MaxCols_> > : tra
   typedef ArrayXpr XprKind;
   typedef ArrayBase<Array<Scalar_, Rows_, Cols_, Options_, MaxRows_, MaxCols_> > XprBase;
 };
+
+template<typename Scalar_, int Rows_, int Cols_, int Options_, int MaxRows_, int MaxCols_>
+struct has_trivially_copyable_storage<Array<Scalar_, Rows_, Cols_, Options_, MaxRows_, MaxCols_> >
+    : has_trivially_copyable_storage<Matrix<Scalar_, Rows_, Cols_, Options_, MaxRows_, MaxCols_> > {};
 }
 
 /** \class Array
@@ -120,6 +124,12 @@ class Array
       return Base::_set(other);
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Array& operator=(
+        const Array& other) requires internal::has_trivially_copyable_storage<Array>::value = default;
+#endif
+
     /** Default constructor.
       *
       * For fixed-size matrices, does nothing.
@@ -159,6 +169,13 @@ class Array
       return *this;
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC Array(Array&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Array>::value = default;
+    EIGEN_DEVICE_FUNC Array& operator=(Array&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Array>::value = default;
+#endif
+
     /** \copydoc PlainObjectBase(const Scalar& a0, const Scalar& a1, const Scalar& a2, const Scalar& a3, const ArgTypes&... args)
      *
      * Example: \include Array_variadic_ctor_cxx11.cpp
@@ -266,6 +283,12 @@ class Array
             : Base(other)
     { }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Array(const Array& other) requires internal::has_trivially_copyable_storage<Array>::value =
+        default;
+#endif
+
   private:
     struct PrivateType {};
   public:
diff --git a/Eigen/src/Core/ArrayBase.h b/Eigen/src/Core/ArrayBase.h
index 28397e5cf..2d6fe4250 100644
--- a/Eigen/src/Core/ArrayBase.h
+++ b/Eigen/src/Core/ArrayBase.h
@@ -112,6 +112,11 @@ template<typename Derived> class ArrayBase
       return derived();
     }
     
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE ArrayBase& operator=(
+        const ArrayBase& other) requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     /** Set all the entries to \a value.
       * \sa DenseBase::setConstant(), DenseBase::fill() */
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
diff --git a/Eigen/src/Core/DenseBase.h b/Eigen/src/Core/DenseBase.h
index d62c851de..6d5a10022 100644
--- a/Eigen/src/Core/DenseBase.h
+++ b/Eigen/src/Core/DenseBase.h
@@ -275,6 +275,11 @@ template<typename Derived> class DenseBase
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     Derived& operator=(const DenseBase& other);
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE DenseBase& operator=(
+        const DenseBase& other) requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     template<typename OtherDerived>
     EIGEN_DEVICE_FUNC
     Derived& operator=(const EigenBase<OtherDerived> &other);
diff --git a/Eigen/src/Core/Matrix.h b/Eigen/src/Core/Matrix.h
index 44c0e258f..77051a0b7 100644
--- a/Eigen/src/Core/Matrix.h
+++ b/Eigen/src/Core/Matrix.h
@@ -52,6 +52,14 @@ public:
     Alignment = actual_alignment
   };
 };
+
+template<typename Scalar_, int Rows_, int Cols_, int Options_, int MaxRows_, int MaxCols_>
+struct has_trivially_copyable_storage<Matrix<Scalar_, Rows_, Cols_, Options_, MaxRows_, MaxCols_> >
+{
+  // Must be identical to the type of PlainObjectBase::m_storage.
+  typedef DenseStorage<Scalar_, internal::size_at_compile_time<MaxRows_, MaxCols_>::ret, Rows_, Cols_, Options_> Storage;
+  static const bool value = std::is_trivially_copyable<Storage>::value;
+};
 }
 
 /** \class Matrix
@@ -210,6 +218,12 @@ class Matrix
       return Base::_set(other);
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Matrix& operator=(
+        const Matrix& other) requires internal::has_trivially_copyable_storage<Matrix>::value = default;
+#endif
+
     /** \internal
       * \brief Copies the value of the expression \a other into \c *this with automatic resizing.
       *
@@ -279,6 +293,13 @@ class Matrix
       return *this;
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Matrix(Matrix&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Matrix>::value = default;
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Matrix& operator=(Matrix&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Matrix>::value = default;
+#endif
+
     /** \copydoc PlainObjectBase(const Scalar&, const Scalar&, const Scalar&,  const Scalar&, const ArgTypes&... args)
      *
      * Example: \include Matrix_variadic_ctor_cxx11.cpp
@@ -404,6 +425,12 @@ class Matrix
     EIGEN_STRONG_INLINE Matrix(const Matrix& other) : Base(other)
     { }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Matrix(const Matrix& other) requires internal::has_trivially_copyable_storage<Matrix>::value =
+        default;
+#endif
+
     /** \brief Copy constructor for generic expressions.
       * \sa MatrixBase::operator=(const EigenBase<OtherDerived>&)
       */
diff --git a/Eigen/src/Core/MatrixBase.h b/Eigen/src/Core/MatrixBase.h
index 70d0cf77f..89a411010 100644
--- a/Eigen/src/Core/MatrixBase.h
+++ b/Eigen/src/Core/MatrixBase.h
@@ -140,6 +140,11 @@ template<typename Derived> class MatrixBase
     EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     Derived& operator=(const MatrixBase& other);
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE MatrixBase& operator=(
+        const MatrixBase& other) requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     // We cannot inherit here via Base::operator= since it is causing
     // trouble with MSVC.
 
diff --git a/Eigen/src/Core/PlainObjectBase.h b/Eigen/src/Core/PlainObjectBase.h
index 4367ea5c0..33ae5072d 100644
--- a/Eigen/src/Core/PlainObjectBase.h
+++ b/Eigen/src/Core/PlainObjectBase.h
@@ -463,6 +463,12 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
       return _set(other);
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE PlainObjectBase& operator=(
+        const PlainObjectBase& other) requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     /** \sa MatrixBase::lazyAssign() */
     template<typename OtherDerived>
     EIGEN_DEVICE_FUNC
@@ -514,10 +520,27 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
       return *this;
     }
 
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    PlainObjectBase(PlainObjectBase&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Derived>::value = default;
+
+    EIGEN_DEVICE_FUNC
+    PlainObjectBase& operator=(PlainObjectBase&& other) EIGEN_NOEXCEPT
+        requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     /** Copy constructor */
     EIGEN_DEVICE_FUNC
     EIGEN_STRONG_INLINE PlainObjectBase(const PlainObjectBase& other)
       : Base(), m_storage(other.m_storage) { }
+
+#if EIGEN_COMP_HAS_P0848R3
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE PlainObjectBase(
+        const PlainObjectBase& other) requires internal::has_trivially_copyable_storage<Derived>::value = default;
+#endif
+
     EIGEN_DEVICE_FUNC
     EIGEN_STRONG_INLINE PlainObjectBase(Index size, Index rows, Index cols)
       : m_storage(size, rows, cols)
diff --git a/Eigen/src/Core/util/ForwardDeclarations.h b/Eigen/src/Core/util/ForwardDeclarations.h
index cb12c77e3..f745914b2 100644
--- a/Eigen/src/Core/util/ForwardDeclarations.h
+++ b/Eigen/src/Core/util/ForwardDeclarations.h
@@ -42,6 +42,11 @@ template<typename T> struct evaluator_traits;
 
 template< typename T> struct evaluator;
 
+template<typename T> struct has_trivially_copyable_storage
+{
+  static const bool value = false;
+};
+
 } // end namespace internal
 
 template<typename T> struct NumTraits;
diff --git a/Eigen/src/Core/util/Macros.h b/Eigen/src/Core/util/Macros.h
index bb1fe5b01..32bb16805 100644
--- a/Eigen/src/Core/util/Macros.h
+++ b/Eigen/src/Core/util/Macros.h
@@ -1084,6 +1084,16 @@ namespace Eigen {
     }
 #endif
 
+/**
+ * \internal
+ * \brief Macro for conditionally trivial special member functions for supporting trivially copyable types.
+ * This feature is officially known as C++20's P0848R3 and is enabled on supported compilers.
+ */
+#if (EIGEN_COMP_CXXVER >= 20) && (EIGEN_COMP_GNUC_STRICT || EIGEN_COMP_MSVC_STRICT)
+#define EIGEN_COMP_HAS_P0848R3 1
+#else
+#define EIGEN_COMP_HAS_P0848R3 0
+#endif
 
 /**
  * \internal
diff --git a/test/dense_storage.cpp b/test/dense_storage.cpp
index 398cb3266..370900014 100644
--- a/test/dense_storage.cpp
+++ b/test/dense_storage.cpp
@@ -20,6 +20,11 @@ static_assert(std::is_trivially_move_assignable<DenseStorageD3x3>::value, "Dense
 static_assert(std::is_trivially_copy_constructible<DenseStorageD3x3>::value, "DenseStorage not trivially_copy_constructible");
 static_assert(std::is_trivially_copy_assignable<DenseStorageD3x3>::value, "DenseStorage not trivially_copy_assignable");
 static_assert(std::is_trivially_copyable<DenseStorageD3x3>::value, "DenseStorage not trivially_copyable");
+#if EIGEN_COMP_HAS_P0848R3
+static_assert(std::is_trivially_copyable<Eigen::Matrix3d>::value, "Eigen::Matrix3d not trivially_copyable");
+static_assert(std::is_trivially_copyable<Eigen::Array33d>::value, "Eigen::Array33d not trivially_copyable");
+static_assert(!std::is_trivially_copyable<Eigen::Matrix3<AnnoyingScalar>>::value, "Eigen::Matrix3<AnnoyingScalar> is trivially_copyable");
+#endif
 #endif
 
 template <typename T, int Size, int Rows, int Cols>
diff --git a/unsupported/Eigen/CXX11/Tensor b/unsupported/Eigen/CXX11/Tensor
index 0a04a0e0c..25f1fb957 100644
--- a/unsupported/Eigen/CXX11/Tensor
+++ b/unsupported/Eigen/CXX11/Tensor
@@ -39,6 +39,16 @@
 #include <iterator>
 #include <numeric>
 #include <random>
+
+// C++20 libstdc++'s headers have non-parenthesized calls to max() and min().
+#if EIGEN_COMP_HAS_P0848R3
+#ifdef max
+#undef max
+#endif
+#ifdef min
+#undef min
+#endif
+#endif
 #include <thread>
 
 #if defined(EIGEN_USE_THREADS) || defined(EIGEN_USE_SYCL)
diff --git a/unsupported/Eigen/CXX11/ThreadPool b/unsupported/Eigen/CXX11/ThreadPool
index 6ebe9e779..4f9600236 100644
--- a/unsupported/Eigen/CXX11/ThreadPool
+++ b/unsupported/Eigen/CXX11/ThreadPool
@@ -39,9 +39,7 @@
 #include <condition_variable>
 #include <deque>
 #include <mutex>
-#include <thread>
 #include <functional>
-#include <memory>
 #include <utility>
 
 // There are non-parenthesized calls to "max" in the  <unordered_map> header,
@@ -53,6 +51,15 @@
 #endif
 #include <unordered_map>
 
+// C++20 libstdc++'s headers also calls "max" and "min" indirectly.
+#if EIGEN_COMP_HAS_P0848R3
+#ifdef min
+#undef min
+#endif
+#endif
+#include <thread>
+#include <memory>
+
 #include "src/util/CXX11Meta.h"
 #include "src/util/MaxSizeVector.h"