From c2d6ab8ee0935d6093dc4dcbe89ea594af71050c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Villemot?= <sebastien@dynare.org>
Date: Fri, 1 Dec 2023 15:06:40 +0100
Subject: [PATCH] Simplify a few loops using std::ranges::reverse_view

Automatically detected using clang-tidy with modernize-loop-convert check.
---
 src/DynamicModel.cc            | 7 ++++---
 src/ModelEquationBlock.cc      | 5 +++--
 src/VariableDependencyGraph.cc | 5 +++--
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/DynamicModel.cc b/src/DynamicModel.cc
index 78ae0ce3..9e807072 100644
--- a/src/DynamicModel.cc
+++ b/src/DynamicModel.cc
@@ -23,6 +23,7 @@
 #include <cstdlib>
 #include <iostream>
 #include <numeric>
+#include <ranges>
 #include <regex>
 #include <sstream>
 #include <string_view>
@@ -3485,18 +3486,18 @@ void
 DynamicModel::detrendEquations()
 {
   // We go backwards in the list of trend_vars, to deal correctly with I(2) processes
-  for (auto it = nonstationary_symbols_map.crbegin(); it != nonstationary_symbols_map.crend(); ++it)
+  for (const auto& it : std::ranges::reverse_view(nonstationary_symbols_map))
     {
       for (auto& equation : equations)
         {
           equation = dynamic_cast<BinaryOpNode*>(
-              equation->detrend(it->first, it->second.first, it->second.second));
+              equation->detrend(it.first, it.second.first, it.second.second));
           assert(equation);
         }
       for (auto& equation : static_only_equations)
         {
           equation = dynamic_cast<BinaryOpNode*>(
-              equation->detrend(it->first, it->second.first, it->second.second));
+              equation->detrend(it.first, it.second.first, it.second.second));
           assert(equation);
         }
     }
diff --git a/src/ModelEquationBlock.cc b/src/ModelEquationBlock.cc
index a2f7a7ba..55247123 100644
--- a/src/ModelEquationBlock.cc
+++ b/src/ModelEquationBlock.cc
@@ -19,6 +19,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <ranges>
 #include <sstream>
 
 #include "ModelEquationBlock.hh"
@@ -385,10 +386,10 @@ void
 Epilogue::detrend(const map<int, expr_t>& trend_symbols_map,
                   const nonstationary_symbols_map_t& nonstationary_symbols_map)
 {
-  for (auto it = nonstationary_symbols_map.crbegin(); it != nonstationary_symbols_map.crend(); ++it)
+  for (const auto& it : ranges::reverse_view(nonstationary_symbols_map))
     for (auto& [symb_id, expr] : dynamic_def_table)
       {
-        expr = expr->detrend(it->first, it->second.first, it->second.second);
+        expr = expr->detrend(it.first, it.second.first, it.second.second);
         assert(expr);
       }
 
diff --git a/src/VariableDependencyGraph.cc b/src/VariableDependencyGraph.cc
index d176417a..7e649ca3 100644
--- a/src/VariableDependencyGraph.cc
+++ b/src/VariableDependencyGraph.cc
@@ -29,6 +29,7 @@
 #include <boost/graph/strong_components.hpp>
 #include <boost/graph/topological_sort.hpp>
 #pragma GCC diagnostic pop
+#include <ranges>
 
 using namespace boost;
 
@@ -325,8 +326,8 @@ VariableDependencyGraph::reorderRecursiveVariables(const set<int>& feedback_vert
   auto v_index = get(vertex_index, G);
 
   // Suppress feedback vertices, in decreasing order
-  for (auto it = feedback_vertices.rbegin(); it != feedback_vertices.rend(); ++it)
-    G.suppress(*it);
+  for (int feedback_vertex : ranges::reverse_view(feedback_vertices))
+    G.suppress(feedback_vertex);
 
   bool something_has_been_done = true;
   while (something_has_been_done)