diff --git a/include/Peanut/impl/binary_expr/matrix_div_scalar.h b/include/Peanut/impl/binary_expr/matrix_div_scalar.h
index c802339..87ec1e4 100644
--- a/include/Peanut/impl/binary_expr/matrix_div_scalar.h
+++ b/include/Peanut/impl/binary_expr/matrix_div_scalar.h
@@ -51,14 +51,14 @@ namespace Peanut::Impl {
         }
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE Float elem(Index r, Index c) const {
+        inline Float elem(Index r, Index c) const {
             return static_cast<Type>(x.elem(r, c)) / static_cast<Float>(y);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/binary_expr/matrix_emult.h b/include/Peanut/impl/binary_expr/matrix_emult.h
index 853c0aa..7bf90ae 100644
--- a/include/Peanut/impl/binary_expr/matrix_emult.h
+++ b/include/Peanut/impl/binary_expr/matrix_emult.h
@@ -46,14 +46,14 @@ namespace Peanut::Impl {
         MatrixEMult(const E1 &x, const E2 &y) : x{x}, y{y} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(r, c) * y.elem(r, c);
         }
 
         static constexpr Index Row = E1::Row;
         static constexpr Index Col = E1::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/binary_expr/matrix_mult.h b/include/Peanut/impl/binary_expr/matrix_mult.h
index dd44e91..5e0a0f9 100644
--- a/include/Peanut/impl/binary_expr/matrix_mult.h
+++ b/include/Peanut/impl/binary_expr/matrix_mult.h
@@ -47,7 +47,7 @@ namespace Peanut::Impl {
         MatrixMult(const E1 &_x, const E2 &_y) : x_eval{_x}, y_eval{_y} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             auto ret = x_eval.elem(r, 0) * y_eval.elem(0, c);
             for (Index i = 1; i < E1::Col; i++) {
                 ret += x_eval.elem(r, i) * y_eval.elem(i, c);
@@ -58,7 +58,7 @@ namespace Peanut::Impl {
         static constexpr Index Row = E1::Row;
         static constexpr Index Col = E2::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/binary_expr/matrix_mult_scalar.h b/include/Peanut/impl/binary_expr/matrix_mult_scalar.h
index 86e1dab..665817f 100644
--- a/include/Peanut/impl/binary_expr/matrix_mult_scalar.h
+++ b/include/Peanut/impl/binary_expr/matrix_mult_scalar.h
@@ -47,14 +47,14 @@ namespace Peanut::Impl {
         MatrixMultScalar(const E &x, T y) : x{x}, y{y} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE Type elem(Index r, Index c) const {
+        inline Type elem(Index r, Index c) const {
             return static_cast<Type>(x.elem(r, c)) * static_cast<Type>(y);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/binary_expr/matrix_subtract.h b/include/Peanut/impl/binary_expr/matrix_subtract.h
index d23d83d..81946f3 100644
--- a/include/Peanut/impl/binary_expr/matrix_subtract.h
+++ b/include/Peanut/impl/binary_expr/matrix_subtract.h
@@ -45,14 +45,14 @@ namespace Peanut::Impl {
         MatrixSubtract(const E1 &x, const E2 &y) : x{x}, y{y} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(r, c) - y.elem(r, c);
         }
 
         static constexpr Index Row = E1::Row;
         static constexpr Index Col = E1::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/binary_expr/matrix_sum.h b/include/Peanut/impl/binary_expr/matrix_sum.h
index d1b4625..a8a12f2 100644
--- a/include/Peanut/impl/binary_expr/matrix_sum.h
+++ b/include/Peanut/impl/binary_expr/matrix_sum.h
@@ -45,14 +45,14 @@ namespace Peanut::Impl {
         MatrixSum(const E1 &x, const E2 &y) : x{x}, y{y} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(r, c) + y.elem(r, c);
         }
 
         static constexpr Index Row = E1::Row;
         static constexpr Index Col = E1::Col;
 
-        INLINE auto eval() const {
+        inline auto eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/common.h b/include/Peanut/impl/common.h
index 4542fa2..d8f4615 100644
--- a/include/Peanut/impl/common.h
+++ b/include/Peanut/impl/common.h
@@ -34,8 +34,6 @@
 
 // Dependencies headers
 
-#define INLINE __attribute__((always_inline)) inline
-
 namespace Peanut {
     using Index = unsigned int;
     using Float = float;
diff --git a/include/Peanut/impl/matrix.h b/include/Peanut/impl/matrix.h
index 571d210..44b88a7 100644
--- a/include/Peanut/impl/matrix.h
+++ b/include/Peanut/impl/matrix.h
@@ -66,7 +66,7 @@ namespace Peanut {
          * @param c C index.
          * @return Rvalue of an element in \p r 'th Row and \p c 'th column.
          */
-        INLINE auto elem(Index r, Index c) const{
+        inline auto elem(Index r, Index c) const{
             return static_cast<const E&>(*this).elem(r, c);
         }
     };
@@ -228,7 +228,7 @@ namespace Peanut {
          * @param c Column index.
          * @return Rvalue of an element in \p r 'th Row and \p c 'th column.
          */
-        INLINE T elem(Index r, Index c) const{
+        inline T elem(Index r, Index c) const{
             return m_data.d2[r][c];
         }
 
@@ -240,7 +240,7 @@ namespace Peanut {
          * @param c Column index.
          * @return Reference of an element in \p r 'th Row and \p c 'th column.
          */
-        INLINE T& elem(Index r, Index c) {
+        inline T& elem(Index r, Index c) {
             return m_data.d2[r][c];
         }
 
@@ -294,7 +294,7 @@ namespace Peanut {
          *        method even though it is not a method of `MatrixExpr`.
          * @return Evaluated matrix
          */
-        INLINE Matrix<Type, Row, Col> eval() const{
+        inline Matrix<Type, Row, Col> eval() const{
             return Matrix<Type, Row, Col>(*this);
         }
 
@@ -306,7 +306,7 @@ namespace Peanut {
          * @param i Index
          * @return \p T type i'th element data.
          */
-        INLINE T operator[](Index i) const
+        inline T operator[](Index i) const
             requires (Row==1) || (Col==1){
             return m_data.d1[i];
         }
@@ -317,7 +317,7 @@ namespace Peanut {
          * @param i Index
          * @return Reference of i'th element.
          */
-        INLINE T& operator[](Index i)
+        inline T& operator[](Index i)
             requires (Row==1) || (Col==1){
             return m_data.d1[i];
         }
@@ -328,7 +328,7 @@ namespace Peanut {
          * @param vec Equal-type matrix(vector).
          * @return T type dot product result.
          */
-        T dot(const Matrix &vec) const requires (Row==1) || (Col==1){
+        inline T dot(const Matrix &vec) const requires (Row==1) || (Col==1){
             T ret = t_0;
             for(int i=0;i<Row*Col;i++){
                 ret += (vec.m_data.d1[i] * m_data.d1[i]);
@@ -341,7 +341,7 @@ namespace Peanut {
          *        (i.e., Row==1 or Col==1)
          * @return Float l2 distance of the vector.
          */
-        Float length() const requires (Row==1) || (Col==1){
+        inline Float length() const requires (Row==1) || (Col==1){
             T ret = t_0;
             for(int i=0;i<Row*Col;i++){
                 ret += (m_data.d1[i] * m_data.d1[i]);
@@ -354,7 +354,7 @@ namespace Peanut {
          *        (i.e., Row==1 or Col==1)
          * @return Normalized Float matrix(vector).
          */
-        Matrix<Float, Row, Col> normalize() const requires (Row==1) || (Col==1){
+        inline Matrix<Float, Row, Col> normalize() const requires (Row==1) || (Col==1){
             Matrix<Float, Row, Col> ret;
             const Float len = length();
             for(int i=0;i<Row*Col;i++){
@@ -368,7 +368,7 @@ namespace Peanut {
          *        (i.e., Row==1 or Col==1)
          * @return Max element in the vector.
          */
-        T max() const requires (Row==1) || (Col==1){
+        inline T max() const requires (Row==1) || (Col==1){
             return *std::max_element(m_data.d1.begin(), m_data.d1.end());
         }
 
@@ -377,7 +377,7 @@ namespace Peanut {
          *        (i.e., Row==1 or Col==1)
          * @return Min element in the vector.
          */
-        T min() const requires (Row==1) || (Col==1){
+        inline T min() const requires (Row==1) || (Col==1){
             return *std::min_element(m_data.d1.begin(), m_data.d1.end());
         }
 
diff --git a/include/Peanut/impl/unary_expr/adjugate.h b/include/Peanut/impl/unary_expr/adjugate.h
index baeb095..f7c855a 100644
--- a/include/Peanut/impl/unary_expr/adjugate.h
+++ b/include/Peanut/impl/unary_expr/adjugate.h
@@ -59,14 +59,14 @@ namespace Peanut::Impl {
         }
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return mat_eval.elem(r, c);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return mat_eval;
         }
 
diff --git a/include/Peanut/impl/unary_expr/block.h b/include/Peanut/impl/unary_expr/block.h
index 756bb7b..e876cff 100644
--- a/include/Peanut/impl/unary_expr/block.h
+++ b/include/Peanut/impl/unary_expr/block.h
@@ -48,14 +48,14 @@ namespace Peanut::Impl {
         MatrixBlock(const E &x) : x{x} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(row_start + r, col_start + c);
         }
 
         static constexpr Index Row = row_size;
         static constexpr Index Col = col_size;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/unary_expr/cast.h b/include/Peanut/impl/unary_expr/cast.h
index 3177d2d..cab41cc 100644
--- a/include/Peanut/impl/unary_expr/cast.h
+++ b/include/Peanut/impl/unary_expr/cast.h
@@ -44,14 +44,14 @@ namespace Peanut::Impl {
         MatrixCastType(const E &x) : x{x} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE T elem(Index r, Index c) const {
+        inline T elem(Index r, Index c) const {
             return static_cast<T>(x.elem(r, c));
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/unary_expr/cofactor.h b/include/Peanut/impl/unary_expr/cofactor.h
index 77f93e4..09efa0c 100644
--- a/include/Peanut/impl/unary_expr/cofactor.h
+++ b/include/Peanut/impl/unary_expr/cofactor.h
@@ -59,14 +59,14 @@ namespace Peanut::Impl {
         }
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return mat_eval.elem(r, c);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return mat_eval;
         }
 
diff --git a/include/Peanut/impl/unary_expr/inverse.h b/include/Peanut/impl/unary_expr/inverse.h
index ddf6ccb..3557dc5 100644
--- a/include/Peanut/impl/unary_expr/inverse.h
+++ b/include/Peanut/impl/unary_expr/inverse.h
@@ -52,14 +52,14 @@ namespace Peanut::Impl {
         }
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE Float elem(Index r, Index c) const {
+        inline Float elem(Index r, Index c) const {
             return invdet * cofactor_eval.elem(c, r);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/unary_expr/minor.h b/include/Peanut/impl/unary_expr/minor.h
index 233ff5a..42afdb0 100644
--- a/include/Peanut/impl/unary_expr/minor.h
+++ b/include/Peanut/impl/unary_expr/minor.h
@@ -51,14 +51,14 @@ namespace Peanut::Impl {
         }
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return mat_eval.elem(r, c);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return mat_eval;
         }
 
diff --git a/include/Peanut/impl/unary_expr/negation.h b/include/Peanut/impl/unary_expr/negation.h
index b7e721f..18acd74 100644
--- a/include/Peanut/impl/unary_expr/negation.h
+++ b/include/Peanut/impl/unary_expr/negation.h
@@ -44,14 +44,14 @@ namespace Peanut::Impl {
         MatrixNegation(const E &x) : x{x} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return -x.elem(r, c);
         }
 
         static constexpr Index Row = E::Row;
         static constexpr Index Col = E::Col;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/unary_expr/submatrix.h b/include/Peanut/impl/unary_expr/submatrix.h
index 031a3c3..8cb25a6 100644
--- a/include/Peanut/impl/unary_expr/submatrix.h
+++ b/include/Peanut/impl/unary_expr/submatrix.h
@@ -47,14 +47,14 @@ namespace Peanut::Impl {
         MatrixSub(const E &x) : x{x} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(r < row_ex ? r : r + 1, c < col_ex ? c : c + 1);
         }
 
         static constexpr Index Row = E::Row - 1;
         static constexpr Index Col = E::Col - 1;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }
 
diff --git a/include/Peanut/impl/unary_expr/transpose.h b/include/Peanut/impl/unary_expr/transpose.h
index f993f8b..a9ffc23 100644
--- a/include/Peanut/impl/unary_expr/transpose.h
+++ b/include/Peanut/impl/unary_expr/transpose.h
@@ -44,14 +44,14 @@ namespace Peanut::Impl {
         MatrixTranspose(const E &x) : x{x} {}
 
         // Static polymorphism implementation of MatrixExpr
-        INLINE auto elem(Index r, Index c) const {
+        inline auto elem(Index r, Index c) const {
             return x.elem(c, r);
         }
 
         static constexpr Index Row = E::Col;
         static constexpr Index Col = E::Row;
 
-        INLINE Matrix<Type, Row, Col> eval() const {
+        inline Matrix<Type, Row, Col> eval() const {
             return Matrix<Type, Row, Col>(*this);
         }