Use = default/delete for trivial C++ class constructors

This is applying clang-tidy's `modernize-use-equals-default` and
`modernize-use-equals-delete` checks.

Author: QuLogic

src/_backend_agg.h

@@ -65,6 +65,10 @@ class BufferRegion
         delete[] data;
     };
 
+    // prevent copying
+    BufferRegion(const BufferRegion &) = delete;
+    BufferRegion &operator=(const BufferRegion &) = delete;
+
     agg::int8u *get_data()
     {
         return data;
@@ -96,11 +100,6 @@ class BufferRegion
     int width;
     int height;
     int stride;
-
-  private:
-    // prevent copying
-    BufferRegion(const BufferRegion &);
-    BufferRegion &operator=(const BufferRegion &);
 };
 
 #define MARKER_CACHE_SIZE 512

src/_image_resample.h

@@ -60,20 +60,16 @@ namespace agg
         value_type a;
 
         //--------------------------------------------------------------------
-        gray64() {}
+        gray64() = default;
 
         //--------------------------------------------------------------------
-        explicit gray64(value_type v_, value_type a_ = 1) :
-        v(v_), a(a_) {}
+        explicit gray64(value_type v_, value_type a_ = 1) : v(v_), a(a_) {}
 
         //--------------------------------------------------------------------
-        gray64(const self_type& c, value_type a_) :
-            v(c.v), a(a_) {}
+        gray64(const self_type& c, value_type a_) : v(c.v), a(a_) {}
 
         //--------------------------------------------------------------------
-        gray64(const gray64& c) :
-            v(c.v),
-            a(c.a) {}
+        gray64(const gray64& c) = default;
 
         //--------------------------------------------------------------------
         static AGG_INLINE double to_double(value_type a)
@@ -246,7 +242,7 @@ namespace agg
         value_type a;
 
         //--------------------------------------------------------------------
-        rgba64() {}
+        rgba64() = default;
 
         //--------------------------------------------------------------------
         rgba64(value_type r_, value_type g_, value_type b_, value_type a_= 1) :

src/array.h

@@ -56,9 +56,7 @@ class empty
   public:
     typedef empty<T> sub_t;
 
-    empty()
-    {
-    }
+    empty() = default;
 
     T &operator()(int i, int j = 0, int k = 0)
     {

src/path_converters.h

@@ -59,9 +59,7 @@ class EmbeddedQueue
 
     struct item
     {
-        item()
-        {
-        }
+        item() = default;
 
         inline void set(const unsigned cmd_, const double x_, const double y_)
         {

src/tri/_tri.cpp

@@ -44,8 +44,7 @@ std::ostream& operator<<(std::ostream& os, const TriEdge& tri_edge)
 
 
 
-XY::XY()
-{}
+XY::XY() = default;
 
 XY::XY(const double& x_, const double& y_)
     : x(x_), y(y_)