support uniqeptr<T> as input arguments

Author: aminroosta

hdr/sqlite_modern_cpp.h

@@ -215,6 +215,7 @@ namespace sqlite {
 		template<typename T> friend void get_col_from_db(database_binder& db, int inx, std::vector<T>& val);
 		/* for nullptr & unique_ptr support */
 		friend database_binder::chain_type& operator <<(database_binder::chain_type& db, std::nullptr_t);
+		template<typename T> friend database_binder::chain_type& operator <<(database_binder::chain_type& db, const std::unique_ptr<T>& val);
 		template<typename T> friend void get_col_from_db(database_binder& db, int inx, std::unique_ptr<T>& val);
 		template<typename T> friend T operator++(database_binder& db, int);
 
@@ -471,6 +472,14 @@ namespace sqlite {
 		++db->_inx;
 		return db;
 	}
+	/* for nullptr support */
+	template<typename T> inline database_binder::chain_type& operator <<(database_binder::chain_type& db, const std::unique_ptr<T>& val) {
+		if(val)
+			db << *val;
+		else
+		  db << nullptr;
+		return db;
+	}
 
 	/* for unique_ptr<T> support */
 	template<typename T> inline void get_col_from_db(database_binder& db, int inx, std::unique_ptr<T>& _ptr_) {

tests/nullptr_uniqueptr.cc

@@ -11,7 +11,8 @@ int main() {
 		database db(":memory:");
 		db << "CREATE TABLE tbl (id integer,age integer, name string, img blob);";
 		db << "INSERT INTO tbl VALUES (?, ?, ?, ?);" << 1 << 24 << "bob" << vector<int> { 1, 2 , 3};
-		db << "INSERT INTO tbl VALUES (?, ?, ?, ?);" << 2 << nullptr << nullptr << nullptr;
+    unique_ptr<string> ptr_null;
+		db << "INSERT INTO tbl VALUES (?, ?, ?, ?);" << 2 << nullptr << ptr_null << nullptr;
 
 		db << "select age,name,img from tbl where id = 1" >> [](unique_ptr<int> age_p, unique_ptr<string> name_p, unique_ptr<vector<int>> img_p) {
       if(age_p == nullptr || name_p == nullptr || img_p == nullptr) {