Macro for generating default serialisation functions (#2177)

* [DLIB] macro for generating default serialisation functions

* [DLIB]  refactoring

* [DLIB]  refactoring

dlib/serialize.h

@@ -1554,7 +1554,7 @@ namespace dlib
             if (!(*fout))
                 throw serialization_error("Unable to open " + filename + " for writing.");
         }
-
+    
         template <typename T>
         inline proxy_serialize& operator<<(const T& item)
         {
@@ -1773,6 +1773,76 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
+    template<typename T>
+    inline void serialize_these(std::ostream& out, const T& x)
+    {
+        using dlib::serialize;
+        serialize(x, out);
+    }
+    
+    template<typename T, typename... Rest>
+    inline void serialize_these(std::ostream& out, const T& x, const Rest& ... rest)
+    {
+        serialize_these(out, x);
+        serialize_these(out, rest...);
+    }
+    
+    template<typename T>
+    inline void deserialize_these(std::istream& in, T& x)
+    {
+        using dlib::deserialize;
+        deserialize(x, in);
+    }
+    
+    template<typename T, typename... Rest>
+    inline void deserialize_these(std::istream& in, T& x, Rest& ... rest)
+    {
+        deserialize_these(in, x);
+        deserialize_these(in, rest...);
+    }  
+    
+    #define DLIB_DEFINE_DEFAULT_SERIALIZATION(Type, ...)    \
+    void serialize_to(std::ostream& out) const              \
+    {                                                       \
+        using dlib::serialize;                              \
+        using dlib::serialize_these;                        \
+        try                                                 \
+        {                                                   \
+            int version = 1;                                \
+            serialize(version, out);                        \
+            serialize_these(out, __VA_ARGS__);              \
+        }                                                   \
+        catch (dlib::serialization_error& e)                \
+        {                                                   \
+            throw dlib::serialization_error(e.info + "\n   while serializing object of type " #Type); \
+        }                                                   \
+    }                                                       \
+                                                            \
+    void deserialize_from(std::istream& in)                 \
+    {                                                       \
+        using dlib::deserialize;                            \
+        using dlib::deserialize_these;                      \
+        try                                                 \
+        {                                                   \
+            int version = 0;                                \
+            deserialize(version, in);                       \
+            if (version != 1)                               \
+                throw dlib::serialization_error("Unexpected version found while deserializing " #Type); \
+            deserialize_these(in, __VA_ARGS__);             \
+        }                                                   \
+        catch (dlib::serialization_error& e)                \
+        {                                                   \
+            throw dlib::serialization_error(e.info + "\n   while deserializing object of type " #Type); \
+        }                                                               \
+    }                                                                   \
+    inline friend void serialize(const Type& item, std::ostream& out)   \
+    {                                                                   \
+        item.serialize_to(out);                                         \
+    }                                                                   \
+    inline friend void deserialize(Type& item, std::istream& in)        \
+    {                                                                   \
+        item.deserialize_from(in);                                      \
+    }
 }
 
 #endif // DLIB_SERIALIZe_

dlib/test/serialize.cpp

@@ -400,7 +400,33 @@ namespace
         dlib::deserialize(item.b_true,in);
         dlib::deserialize(item.b_false,in);
     }
+    
+    struct my_custom_type
+    {
+        int a;
+        float b;
+        std::vector<float> c;
+
+        bool operator==(const my_custom_type& rhs) const
+        {
+            return std::tie(a,b,c) == std::tie(rhs.a, rhs.b, rhs.c);
+        }
+
+        DLIB_DEFINE_DEFAULT_SERIALIZATION(my_custom_type, a, b, c);
+    };
+
+    struct my_custom_type_array
+    {
+        std::vector<my_custom_type> v;
+
+        bool operator==(const my_custom_type_array& rhs) const
+        {
+            return v == rhs.v;
+        }
 
+        DLIB_DEFINE_DEFAULT_SERIALIZATION(my_custom_type_array, v);
+    };
+    
 // ----------------------------------------------------------------------------------------
 
     // This function returns the contents of the file 'stuff.bin' but using the old 
@@ -1027,6 +1053,29 @@ namespace
             DLIB_TEST(B == b);
         }
     }
+    
+    void test_macros()
+    {
+        my_custom_type t1, t2, t3, t4;
+        t1.a = 1;
+        t1.b = 2.5;
+        t1.c.resize(1024);
+
+        t2.a = 2;
+        t2.b = 4.0;
+        t2.c.resize(10);
+
+        my_custom_type_array v1, v2;
+        v1.v.push_back(t1);
+        v1.v.push_back(t2);
+
+        dlib::serialize("serialization_test_macros.dat") << t1 << t2 << v1;
+        dlib::deserialize("serialization_test_macros.dat") >> t3 >> t4 >> v2;
+
+        DLIB_TEST(t1 == t3);
+        DLIB_TEST(t2 == t4);
+        DLIB_TEST(v1 == v2);
+    }
 
 // ----------------------------------------------------------------------------------------
 
@@ -1056,6 +1105,7 @@ namespace
             test_array2d_and_matrix_serialization();
             test_strings();
             test_std_array();
+            test_macros();
         }
     } a;