From d0e3c71b91f1a1c1780158789fd42b8ac7209495 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?louiz=E2=80=99?= <louiz@louiz.org>
Date: Sat, 17 Mar 2018 17:28:41 +0100
Subject: Revert "Use if constexpr to make things a lot more readable"

This reverts commit d62ca9f87906be6f046fe9d07afb8bfb69c166e3.
---
 src/database/insert_query.hpp | 91 ++++++++++++++++++++++++-------------------
 1 file changed, 51 insertions(+), 40 deletions(-)

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

diff --git a/src/database/insert_query.hpp b/src/database/insert_query.hpp
index ed1944f..04c098c 100644
--- a/src/database/insert_query.hpp
+++ b/src/database/insert_query.hpp
@@ -11,17 +11,20 @@
 #include <tuple>
 
 template <std::size_t N=0, typename... T>
-void update_autoincrement_id(std::tuple<T...>& columns, Statement& statement)
+typename std::enable_if<N < sizeof...(T), void>::type
+update_autoincrement_id(std::tuple<T...>& columns, Statement& statement)
 {
-  if constexpr(N < sizeof...(T))
-    {
-      using ColumnType = typename std::decay<decltype(std::get<N>(columns))>::type;
-      if (std::is_same<ColumnType, Id>::value)
-        auto&& column = std::get<Id>(columns);
-      update_autoincrement_id<N + 1>(columns, statement);
-    }
+  using ColumnType = typename std::decay<decltype(std::get<N>(columns))>::type;
+  if (std::is_same<ColumnType, Id>::value)
+    auto&& column = std::get<Id>(columns);
+  update_autoincrement_id<N+1>(columns, statement);
 }
 
+template <std::size_t N=0, typename... T>
+typename std::enable_if<N == sizeof...(T), void>::type
+update_autoincrement_id(std::tuple<T...>&, Statement&)
+{}
+
 struct InsertQuery: public Query
 {
   template <typename... T>
@@ -50,20 +53,23 @@ struct InsertQuery: public Query
   }
 
   template <int N=0, typename... T>
-  void bind_param(const std::tuple<T...>& columns, Statement& statement, int index=1)
+  typename std::enable_if<N < sizeof...(T), void>::type
+  bind_param(const std::tuple<T...>& columns, Statement& statement, int index=1)
   {
-    if constexpr(N < sizeof...(T))
-      {
-        auto&& column = std::get<N>(columns);
-        using ColumnType = std::decay_t<decltype(column)>;
+    auto&& column = std::get<N>(columns);
+    using ColumnType = std::decay_t<decltype(column)>;
 
-        if constexpr(!std::is_same<ColumnType, Id>::value)
-          actual_bind(statement, column.value, index++);
+    if (!std::is_same<ColumnType, Id>::value)
+      actual_bind(statement, column.value, index++);
 
-        this->bind_param<N + 1>(columns, statement, index);
-      }
+    this->bind_param<N+1>(columns, statement, index);
   }
 
+  template <int N=0, typename... T>
+  typename std::enable_if<N == sizeof...(T), void>::type
+  bind_param(const std::tuple<T...>&, Statement&, int)
+  {}
+
   template <typename... T>
   void insert_values(const std::tuple<T...>& columns)
   {
@@ -73,21 +79,23 @@ struct InsertQuery: public Query
   }
 
   template <int N=0, typename... T>
-  void insert_value(const std::tuple<T...>& columns, int index=1)
+  typename std::enable_if<N < sizeof...(T), void>::type
+  insert_value(const std::tuple<T...>& columns, int index=1)
   {
-    if constexpr(N < sizeof...(T))
+    using ColumnType = std::decay_t<decltype(std::get<N>(columns))>;
+
+    if (!std::is_same<ColumnType, Id>::value)
       {
-        using ColumnType = std::decay_t<decltype(std::get<N>(columns))>;
-
-        if (!std::is_same<ColumnType, Id>::value)
-          {
-            this->body += "$" + std::to_string(index++);
-            if (N != sizeof...(T) - 1)
-              this->body += ", ";
-          }
-        this->insert_value<N + 1>(columns, index);
+        this->body += "$" + std::to_string(index++);
+        if (N != sizeof...(T) - 1)
+          this->body += ", ";
       }
+    this->insert_value<N+1>(columns, index);
   }
+  template <int N=0, typename... T>
+  typename std::enable_if<N == sizeof...(T), void>::type
+  insert_value(const std::tuple<T...>&, const int)
+  { }
 
   template <typename... T>
   void insert_col_names(const std::tuple<T...>& columns)
@@ -98,21 +106,24 @@ struct InsertQuery: public Query
   }
 
   template <int N=0, typename... T>
-  void insert_col_name(const std::tuple<T...>& columns)
+  typename std::enable_if<N < sizeof...(T), void>::type
+  insert_col_name(const std::tuple<T...>& columns)
   {
-    if constexpr(N < sizeof...(T))
-      {
-        using ColumnType = std::decay_t<decltype(std::get<N>(columns))>;
+    using ColumnType = std::decay_t<decltype(std::get<N>(columns))>;
 
-        if (!std::is_same<ColumnType, Id>::value)
-          {
-            this->body += ColumnType::name;
-
-            if (N < (sizeof...(T) - 1))
-              this->body += ", ";
-          }
+    if (!std::is_same<ColumnType, Id>::value)
+      {
+        this->body += ColumnType::name;
 
-        this->insert_col_name<N + 1>(columns);
+        if (N < (sizeof...(T) - 1))
+          this->body += ", ";
       }
+
+    this->insert_col_name<N+1>(columns);
   }
+
+  template <int N=0, typename... T>
+  typename std::enable_if<N == sizeof...(T), void>::type
+  insert_col_name(const std::tuple<T...>&)
+  {}
 };
-- 
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