From cf56b60fd340dc62f90b5b8d3c86d68da347abee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?louiz=E2=80=99?= <louiz@louiz.org>
Date: Sat, 8 Jul 2017 12:36:08 +0200
Subject: =?UTF-8?q?Remove=20all=20the=20empty=20=E2=80=9Coptions=E2=80=9D?=
 =?UTF-8?q?=20members=20in=20Column=20classes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

By using SFINAE to use that member only when it exists.
---
 src/database/table.hpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

(limited to 'src/database/table.hpp')

diff --git a/src/database/table.hpp b/src/database/table.hpp
index 411ac6a..f2f70bb 100644
--- a/src/database/table.hpp
+++ b/src/database/table.hpp
@@ -28,6 +28,17 @@ void add_column_to_table(sqlite3* db, const std::string& table_name)
     }
 }
 
+
+template <typename ColumnType, decltype(ColumnType::options) = nullptr>
+void append_option(std::string& s)
+{
+  s += " "s + ColumnType::options;
+}
+
+template <typename>
+void append_option(...)
+{ }
+
 template <typename... T>
 class Table
 {
@@ -110,14 +121,13 @@ class Table
     str += ColumnType::name;
     str += " ";
     str += TypeToSQLType<RealType>::type;
-    str += " "s + ColumnType::options;
+    append_option<ColumnType>(str);
     if (N != sizeof...(T) - 1)
       str += ",";
     str += "\n";
 
     add_column_create<N+1>(str);
   }
-
   template <std::size_t N=0>
   typename std::enable_if<N == sizeof...(T), void>::type
   add_column_create(std::string&)
-- 
cgit v1.2.3