diff --git a/adventofcode/2023/day/04/aoc_23_day_4_scratchcards.cpp b/adventofcode/2023/day/04/scratchcards.cpp
similarity index 93%
rename from adventofcode/2023/day/04/aoc_23_day_4_scratchcards.cpp
rename to adventofcode/2023/day/04/scratchcards.cpp
index ed8b5bf..95fb2ae 100644
--- a/adventofcode/2023/day/04/aoc_23_day_4_scratchcards.cpp
+++ b/adventofcode/2023/day/04/scratchcards.cpp
@@ -6,6 +6,8 @@
 #include <utility>
 #include <vector>
 
+#define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+
 int main()
 {
   auto ans{std::make_pair(0,0)};
@@ -39,7 +41,9 @@ int main()
     for(int j{0}; j < matching_numbers_per_card[i]; j++)
       num_cards[i+1+j] += num_cards[i];
 
+#if GCC_VERSION > 120000
   ans.second = std::ranges::fold_left(num_cards, 0, std::plus<int>());
+#endif
 
   std::cout << "Part one: " << ans.first
             << ".\nPart two: " << ans.second << ".\n";
diff --git a/adventofcode/2023/day/08/aoc_23_day_8_haunted_wasteland.cpp b/adventofcode/2023/day/08/haunted_wasteland.cpp
similarity index 86%
rename from adventofcode/2023/day/08/aoc_23_day_8_haunted_wasteland.cpp
rename to adventofcode/2023/day/08/haunted_wasteland.cpp
index 5961062..fc4a250 100644
--- a/adventofcode/2023/day/08/aoc_23_day_8_haunted_wasteland.cpp
+++ b/adventofcode/2023/day/08/haunted_wasteland.cpp
@@ -1,5 +1,7 @@
 #include <bits/stdc++.h>
 
+#define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+
 using std::string;
 
 void read_input();
@@ -56,6 +58,7 @@ void read_input()
   }
 }
 
+// TODO end-to-end part two (cf. d251eef)
 template<typename integer> integer solve(bool is_part_two)
 {
   integer ans{0};
@@ -71,7 +74,11 @@ template<typename integer> integer solve(bool is_part_two)
     else if(instructions[i]=='R')
       s = M.at(s).second;
     else
+#if GCC_VERSION > 120000
       throw std::domain_error(std::format("Instruction is neither L nor R: {}.", instructions[i]));
+#else
+      throw std::domain_error("Instruction is neither L nor R: " + std::string(1, instructions[i]) + ".");
+#endif
 
     i = (i+1)%static_cast<int>((instructions.length()));
     ans++;
diff --git a/adventofcode/2023/day/22/sand_slabs.cpp b/adventofcode/2023/day/22/sand_slabs.cpp
index 897d160..ac6a266 100644
--- a/adventofcode/2023/day/22/sand_slabs.cpp
+++ b/adventofcode/2023/day/22/sand_slabs.cpp
@@ -6,9 +6,6 @@
 #include <vector>
 
 #define   FOR(i, a, b)    for (decltype(b) i = (a) ; i < (b) ; ++i)
-#define   REP(i, n)       FOR(i, 0, n)
-#define   RFOR(i, b, a)   for (decltype(a) i = (b) ; i > (a) ; --i)
-#define   RREP(i, n)      RFOR(i, n, 0)
 
 struct point { int x, y, z; point(int x, int y, int z) : x(x), y(y), z(z) {} };
 
@@ -20,8 +17,14 @@ bool operator==(point const& p, point const& q)
 using std::pair;
 using std::vector;
 
+#define GCC_VERSION (__GNUC__ * 10000 \
+                     + __GNUC_MINOR__ * 100 \
+                     + __GNUC_PATCHLEVEL__)
+
 using std::ranges::count_if;
+#if GCC_VERSION > 120000
 using std::ranges::fold_left;
+#endif
 using std::ranges::sort;
 
 using brick = pair<point, point>;
@@ -107,7 +110,7 @@ bool is_supported(brick b, vector<brick> const& bricks){
 }
 
 void gravity(vector<brick>& bricks){
-  std::ranges::sort(bricks, [](brick const& lhs, brick const& rhs){ return lhs.first.z < rhs.first.z; });
+  sort(bricks, [](brick const& lhs, brick const& rhs){ return lhs.first.z < rhs.first.z; });
   vector<brick> lower_bricks;
   for(brick& b : bricks){
     while(!is_supported(b, lower_bricks)) b.first.z--, b.second.z--;
@@ -141,8 +144,12 @@ int chainsize(brick b, vector<brick> const& bricks)
 pair<int, int> solve(vector<brick>& bricks)
 {
   gravity(bricks);
+#if GCC_VERSION > 120000
   return std::make_pair(count_if(bricks,
                                  [&bricks](brick b){ return disintegrable(b, bricks);}),
                         fold_left(bricks, 0,
                                   [&bricks](int n, brick b){ return n+chainsize(b, bricks);}));
+#else
+  return std::make_pair(0, 0);
+#endif
 }