smx => max(toDouble(), sp)

+# 5.6.1
+
+- add smx => max(toDouble(), sp) , for example: 12.smx
+
 # 5.6.0
+
 - bug fix: #434
 - add w and h on EdgeInsets,Radius,BorderRadius,BoxConstraints
 
 # 5.5.4
+
 - Bug Fix: False sizes when using DevicePreview
 
 # 5.5.3+2
+
 - Fix #398
 
 # 5.5.3+1
+
 - Fix compatibility with flutter sdk 2.x
 
 # 5.5.3
+
 - Bug Fix: Some widgets disapear because of parent rebuild.
 - Bug Fix: issue #362. Null check operator used on a null value when using ScreenUtil.init().
 - Re-add context to builder parameters **(users request)**.
 - Add some standard rebuild factors.
 
 # 5.5.2
+
 - Add rebuildFactor property
 - Bug Fix: False sizes when resizing
 
 # 5.5.1
+
 - Bug Fix: Assertion Failed (Find MediaQuery in ancestors)
 - Some performance improvements and fixes
 
 # 5.5.0
+
 - Bug Fix: Reaching context that no longer used.
 
 # 5.4.0+1
+
 - delete log
 
 # 5.4.0
+
 - merge #352
 
 # 5.3.1
-- add num.verticalSpacingRadius
-  num.horizontalSpaceRadius
-  num.setVerticalSpacingFromWidth
+
+- add num.verticalSpacingRadius num.horizontalSpaceRadius num.setVerticalSpacingFromWidth
 - update num.horizontalSpace
-  
+
 # 5.3.0
-- For the size, use the context to get it first, which needs to provide the Context
-  More rigorous context checking
+
+- For the size, use the context to get it first, which needs to provide the Context More rigorous
+  context checking
 
 # 5.2.0
 
 - Rollback of 5.1.1 commit
 - Fix the problem of inaccurate height
 - merge #332(https://github.com/OpenFlutter/flutter_screenutil/pull/332)
-  add
-  num.setVerticalSpacing  // SizedBox(height: num * scaleHeight)
-  num.horizontalSpace  // SizedBox(height: num * scaleWidth)
+  add num.setVerticalSpacing // SizedBox(height: num * scaleHeight)
+  num.horizontalSpace // SizedBox(height: num * scaleWidth)
 
 # 5.1.1
 

@@ -35,6 +35,7 @@ class HomePageScaffold extends StatelessWidget {
         child: Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: <Widget>[
+            RSizedBox.square(dimension: 20),
             Row(
               children: <Widget>[
                 // Using Extensions

@@ -22,6 +22,8 @@ extension SizeExtension on num {
   ///I think that it is good for save size balance on big sizes of screen
   double get sm => min(toDouble(), sp);
 
+  double get smx => max(toDouble(), sp);
+
   ///屏幕宽度的倍数
   ///Multiple of screen width
   double get sw => ScreenUtil().screenWidth * this;