diff --git a/src/base.cc b/src/base.cc
index 04ba8c7..b10b960 100644
--- a/src/base.cc
+++ b/src/base.cc
@@ -17,7 +17,7 @@ namespace php_arma
     PHP_ARMA_METHOD(base, nElem, T, T1)
     {
         zend_long count;
-        count_elements(getThis(), &count);
+        count_elements(&EX(This), &count);
         RETVAL_LONG(count);
     }
 
diff --git a/src/complex.cc b/src/complex.cc
index 9bdd70e..522c9cc 100644
--- a/src/complex.cc
+++ b/src/complex.cc
@@ -31,7 +31,7 @@ namespace php_arma
         auto has_imag = num_args == 2;
         auto has_real = num_args > 0;
 
-        auto current = Z_OBJ_P(getThis());
+        auto current = Z_OBJ(EX(This));
         
         if (EXPECTED(has_real)) {
             if (!zval_check_scalar<T>(real)) {
@@ -77,7 +77,7 @@ namespace php_arma
             Z_PARAM_ZVAL(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        if (!operators::add(getThis(), other, return_value)) {
+        if (!operators::add(&EX(This), other, return_value)) {
             ex_bad_type<T>(other);
         }
     }
@@ -90,7 +90,7 @@ namespace php_arma
             Z_PARAM_ZVAL(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        if (!operators::sub(getThis(), other, return_value)) {
+        if (!operators::sub(&EX(This), other, return_value)) {
             ex_bad_type<T>(other);
         }
     }
@@ -98,7 +98,7 @@ namespace php_arma
     template <typename T>
     PHP_ARMA_METHOD(complex, neg, T)
     {
-        operators::neg(getThis(), return_value);
+        operators::neg(&EX(This), return_value);
     }
         
     template <typename T>
@@ -109,7 +109,7 @@ namespace php_arma
             Z_PARAM_ZVAL(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        if (!operators::mul(getThis(), other, return_value)) {
+        if (!operators::mul(&EX(This), other, return_value)) {
             ex_bad_type<T>(other);
         }
     }
@@ -122,7 +122,7 @@ namespace php_arma
             Z_PARAM_ZVAL(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        if (!operators::div(getThis(), other, return_value)) {
+        if (!operators::div(&EX(This), other, return_value)) {
             ex_bad_type<T>(other);
         }
     }
@@ -130,48 +130,48 @@ namespace php_arma
     template <typename T>
     PHP_ARMA_METHOD(complex, abs, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::abs(current));
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, arg, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::arg(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, norm, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::norm(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, conj, T)
     {
-        operators::conj(getThis(), nullptr, return_value);
+        operators::conj(&EX(This), nullptr, return_value);
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, exp, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::exp(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, log, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::log(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, log10, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::log10(current));
     }
         
@@ -183,7 +183,7 @@ namespace php_arma
             Z_PARAM_ZVAL(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        if (!operators::pow(getThis(), other, return_value)) {
+        if (!operators::pow(&EX(This), other, return_value)) {
             ex_bad_type<T>(other);
         }
     }
@@ -191,91 +191,91 @@ namespace php_arma
     template <typename T>
     PHP_ARMA_METHOD(complex, sqrt, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::abs(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, sin, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::sin(current));
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, cos, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::cos(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, tan, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::tan(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, asin, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::asin(current));
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, acos, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::acos(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, atan, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::atan(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, sinh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::sinh(current));
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, cosh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::cosh(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, tanh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::tanh(current));
     }
 
     template <typename T>
     PHP_ARMA_METHOD(complex, asinh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::asinh(current));
     }
         
     template <typename T>
     PHP_ARMA_METHOD(complex, acosh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::acosh(current));
     }
     
     template <typename T>
     PHP_ARMA_METHOD(complex, atanh, T)
     {
-        auto current = zval_get_scalar<native_t>(getThis());
+        auto current = zval_get_scalar<native_t>(&EX(This));
         zval_set_scalar(return_value, std::atanh(current));
     }
 
diff --git a/src/constants.hh b/src/constants.hh
index b061bae..f1c0d71 100644
--- a/src/constants.hh
+++ b/src/constants.hh
@@ -27,21 +27,21 @@ namespace php_arma
         static void invoke(T *obj, zend_long val)
         {
             switch (val) {
-                case fill::none:
+                case none:
                     break;
-                case fill::zeros:
+                case zeros:
                     obj->zeros();
                     break;
-                case fill::ones:
+                case ones:
                     obj->ones();
                     break;
-                case fill::eye:
+                case eye:
                     obj->eye();
                     break;
-                case fill::randu:
+                case randu:
                     obj->randu();
                     break;
-                case fill::randn:
+                case randn:
                     obj->randn();
                     break;
                 default:
@@ -69,22 +69,22 @@ namespace php_arma
         static arma::file_type native(zend_long val)
         {
             switch (val) {
-                case file_type::auto_detect:
+                case auto_detect:
                     return arma::file_type::auto_detect;
-                case file_type::arma_binary:
+                case arma_binary:
                     return arma::file_type::arma_binary;
-                case file_type::arma_ascii:
+                case arma_ascii:
                     return arma::file_type::arma_ascii;
-                case file_type::raw_binary:
+                case raw_binary:
                     return arma::file_type::raw_binary;
-                case file_type::csv_ascii:
+                case csv_ascii:
                     return arma::file_type::csv_ascii;
-                case file_type::coord_ascii:
+                case coord_ascii:
                     return arma::file_type::coord_ascii;
-                case file_type::pgm_binary:
+                case pgm_binary:
                     return arma::file_type::pgm_binary;
 #ifdef ARMA_USE_HDF5
-                case file_type::hdf5_binary:
+                case hdf5_binary:
                     return arma::file_type::hdf5_binary;
 #endif // ARMA_USE_HDF5
                 default:
@@ -102,6 +102,23 @@ namespace php_arma
         static constexpr auto descend        = 1;
         static constexpr auto strict_ascend  = 2;
         static constexpr auto strict_descend = 3;
+
+        zend_always_inline
+        static const char *native(zend_long val)
+        {
+            switch (val) {
+                case ascend:
+                    return "ascend";
+                case descend:
+                    return "decend";
+                case strict_ascend:
+                    return "strictascend";
+                case strict_descend:
+                    return "strictdescend";
+                default:
+                    return nullptr;
+            }
+        }
     };
 
     constexpr const char sort_direction_php_name[] = "SortDirection";
diff --git a/src/dense.cc b/src/dense.cc
index 9a94bd2..0ad6fe4 100644
--- a/src/dense.cc
+++ b/src/dense.cc
@@ -18,7 +18,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::equals(getThis(), other, return_value);
+        operators::equals(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
@@ -29,7 +29,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::not_equals(getThis(), other, return_value);
+        operators::not_equals(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
@@ -40,7 +40,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::greater_than(getThis(), other, return_value);
+        operators::greater_than(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
@@ -51,7 +51,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::smaller_than(getThis(), other, return_value);
+        operators::smaller_than(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
@@ -62,7 +62,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::not_greater_than(getThis(), other, return_value);
+        operators::not_greater_than(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
@@ -73,7 +73,7 @@ namespace php_arma
             Z_PARAM_OBJECT(other)
         ZEND_PARSE_PARAMETERS_END();
 
-        operators::not_smaller_than(getThis(), other, return_value);
+        operators::not_smaller_than(&EX(This), other, return_value);
     }
 
     template <typename T, typename T1>
diff --git a/src/dense_resizable_matrix.cc b/src/dense_resizable_matrix.cc
index 2772f5e..ea4e262 100644
--- a/src/dense_resizable_matrix.cc
+++ b/src/dense_resizable_matrix.cc
@@ -5,6 +5,7 @@
 //
 
 #include "dense_resizable_matrix.hh"
+#include "constants.hh"
 #include "dense_matrix.hh"
 #include "resizable_matrix.hh"
 #include "mat.hh"
@@ -14,19 +15,49 @@ namespace php_arma
     template <typename T, typename T1>
     PHP_ARMA_METHOD(dense_resizable_matrix, ones, T, T1)
     {
-        
+        zend_long n_rows = 0;
+        zend_long n_cols = 0;
+        ZEND_PARSE_PARAMETERS_START(0, 2)
+            Z_PARAM_OPTIONAL
+            Z_PARAM_LONG(n_rows)
+            Z_PARAM_LONG(n_cols)
+        ZEND_PARSE_PARAMETERS_END();
+
+        auto native = THIS_NATIVE;
+        native->ones(n_rows, n_cols);
+        RETVAL_THIS();
     }
 
     template <typename T, typename T1>
     PHP_ARMA_METHOD(dense_resizable_matrix, randu, T, T1)
     {
-        
+        zend_long n_rows = 0;
+        zend_long n_cols = 0;
+        ZEND_PARSE_PARAMETERS_START(0, 2)
+            Z_PARAM_OPTIONAL
+            Z_PARAM_LONG(n_rows)
+            Z_PARAM_LONG(n_cols)
+        ZEND_PARSE_PARAMETERS_END();
+
+        auto native = THIS_NATIVE;
+        native->randu(n_rows, n_cols);
+        RETVAL_THIS();
     }
 
     template <typename T, typename T1>
     PHP_ARMA_METHOD(dense_resizable_matrix, randn, T, T1)
     {
-        
+        zend_long n_rows = 0;
+        zend_long n_cols = 0;
+        ZEND_PARSE_PARAMETERS_START(0, 2)
+            Z_PARAM_OPTIONAL
+            Z_PARAM_LONG(n_rows)
+            Z_PARAM_LONG(n_cols)
+        ZEND_PARSE_PARAMETERS_END();
+
+        auto native = THIS_NATIVE;
+        native->randn(n_rows, n_cols);
+        RETVAL_THIS();
     }
 
     template <typename T, typename T1>
@@ -41,16 +72,37 @@ namespace php_arma
         
     }
 
-    template <typename T, typename T1>
-    PHP_ARMA_METHOD(dense_resizable_matrix, swap, T, T1)
+    template <typename T, typename ChildT>
+    PHP_ARMA_METHOD(dense_resizable_matrix, swap, T, ChildT)
     {
+        zval *other;
+        ZEND_PARSE_PARAMETERS_START(1, 1)
+            Z_PARAM_OBJECT(other)
+        ZEND_PARSE_PARAMETERS_END();
+
+        auto native = THIS_NATIVE;
         
+        if (UNEXPECTED(ChildT::ce != Z_OBJCE_P(other))) {
+            ex_bad_type(zval_get_type_name(&EX(This)), zval_get_type_name(other));
+            return;
+        }
+
+        native->swap(*Z_NATIVE_OBJ_P(other));
     }
 
     template <typename T, typename T1>
     PHP_ARMA_METHOD(dense_resizable_matrix, isSorted, T, T1)
     {
-        
+        zend_long sort_direction = sort_direction::ascend;
+        zend_long dim            = 0;
+        ZEND_PARSE_PARAMETERS_START(0, 2)
+            Z_PARAM_OPTIONAL
+            Z_PARAM_LONG(sort_direction)
+            Z_PARAM_LONG(dim)
+        ZEND_PARSE_PARAMETERS_END();
+
+        auto native = THIS_NATIVE;
+        RETVAL_BOOL(native->is_sorted(sort_direction::native(sort_direction), dim));
     }
 
     template <typename T, typename T1>
diff --git a/src/mapval.cc b/src/mapval.cc
index 4765c2c..1a81df6 100644
--- a/src/mapval.cc
+++ b/src/mapval.cc
@@ -14,7 +14,7 @@ namespace php_arma
     template <typename T, bool B1, bool B2>
     PHP_ARMA_METHOD(mapval, val, T, B1, B2)
     {
-        auto current = Z_OBJ_P(getThis());
+        auto current = Z_OBJ(EX(This));
         zval_set_scalar(return_value, get_val(current));
     }
 
@@ -30,7 +30,7 @@ namespace php_arma
             return;
         }
 
-        auto current = Z_OBJ_P(getThis());
+        auto current = Z_OBJ(EX(This));
         set_val(current, zval_get_scalar<T>(val));
     }
 
diff --git a/src/php_arma.hh b/src/php_arma.hh
index 05d4891..238b3ab 100644
--- a/src/php_arma.hh
+++ b/src/php_arma.hh
@@ -47,7 +47,7 @@
     template class parent<zend_long, child<zend_long>>;   \
     template class parent<cx_double, child<cx_double>>
 
-/// Helper macros for class entry and object handlers
+/// Helper macros for class entry and object handlers.
 
 #define PHP_ARMA_CE_HANDLRES_DECLARE()                    \
     static inline zend_class_entry     *ce;               \
@@ -112,7 +112,12 @@
     to_native_object<native_t>(zobj)
 
 #define Z_NATIVE_OBJ_P(zv)   ZOBJ_NATIVE(Z_OBJ_P(zv))
-#define THIS_NATIVE          Z_NATIVE_OBJ_P(getThis())
+#define THIS_NATIVE          Z_NATIVE_OBJ_P(&EX(This))
+
+/// Misc helper macros.
+
+#define RETVAL_THIS()                                     \
+    ZVAL_COPY(return_value, &EX(This))
 
 namespace php_arma
 {
diff --git a/src/resizable_matrix.cc b/src/resizable_matrix.cc
index f326b26..62f9793 100644
--- a/src/resizable_matrix.cc
+++ b/src/resizable_matrix.cc
@@ -65,6 +65,7 @@ namespace php_arma
 
         auto native = THIS_NATIVE;
         native->zeros(n_rows, n_cols);
+        RETVAL_THIS();
     }
 
     template <typename T, typename T1>
@@ -80,6 +81,7 @@ namespace php_arma
 
         auto native = THIS_NATIVE;
         native->eye(n_rows, n_cols);
+        RETVAL_THIS();
     }
 
     template <typename T, typename T1>