--- a/rust/integral-geometry/src/lib.rs	Sat Mar 23 01:07:23 2019 +0300
+++ b/rust/integral-geometry/src/lib.rs	Sat Mar 23 03:44:11 2019 +0300
@@ -109,6 +109,8 @@
 }
 
 impl Size {
+    pub const EMPTY: Self = Self::square(0);
+
     #[inline]
     pub const fn new(width: usize, height: usize) -> Self {
         Self { width, height }
@@ -163,6 +165,11 @@
     pub fn to_grid_index(&self) -> GridIndex {
         GridIndex::new(*self)
     }
+
+    #[inline]
+    pub fn contains(&self, other: Self) -> bool {
+        self.width >= other.width && self.height >= other.height
+    }
 }
 
 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
@@ -302,6 +309,11 @@
 }
 
 impl Rect {
+    pub const EMPTY: Self = Self {
+        top_left: Point::ZERO,
+        bottom_right: Point::ZERO,
+    };
+
     #[inline]
     pub fn new(top_left: Point, bottom_right: Point) -> Self {
         debug_assert!(top_left.x <= bottom_right.x + 1);
@@ -416,6 +428,11 @@
     }
 
     #[inline]
+    pub fn contains_rect(&self, other: &Self) -> bool {
+        self.contains(other.top_left()) && self.contains(other.bottom_right())
+    }
+
+    #[inline]
     pub fn intersects(&self, other: &Rect) -> bool {
         self.left() <= self.right()
             && self.right() >= other.left()
@@ -435,6 +452,16 @@
     }
 
     #[inline]
+    pub fn with_margins(&self, left: i32, right: i32, top: i32, bottom: i32) -> Self {
+        Self::from_box(
+            self.left() + left,
+            self.right() + right,
+            self.top() + top,
+            self.bottom() + bottom,
+        )
+    }
+
+    #[inline]
     pub fn quotient(self, x: usize, y: usize) -> Point {
         self.top_left() + Point::new((x % self.width()) as i32, (y % self.height()) as i32)
     }