Best I can do to simplify the check(fmt::format)crap is to make a little macro to do the format part.

src/algos/dinkyecs.hpp

@@ -69,8 +69,8 @@ namespace DinkyECS
 
       for(auto [eid, is_set] : $constants) {
         dbc::check(is_set == true, "is_set was not true? WHAT?!");
-        dbc::check(eid <= entity_count, fmt::format(
-              "eid {} is not less than entity_count {}", eid, entity_count));
+        dbc::check(eid <= entity_count,
+            $F("eid {} is not less than entity_count {}", eid, entity_count));
 
         for(const auto &[tid, eid_map] : $components) {
           auto &their_map = to_world.$components[tid];
@@ -146,8 +146,7 @@ namespace DinkyECS
       Comp &get_the() {
         auto comp_id = std::type_index(typeid(Comp));
         dbc::check($facts->contains(comp_id),
-            fmt::format("!!!! ATTEMPT to access world fact that hasn't "
-              "been set yet: {}",
+            $F("!!!! ATTEMPT to access world fact that hasn't been set yet: {}",
               typeid(Comp).name()));
 
         // use .at to get std::out_of_range if fact not set

src/algos/pathing.cpp

@@ -17,10 +17,10 @@ inline void add_neighbors(PointList &neighbors, Matrix &closed, size_t y, size_t
 void Pathing::compute_paths(Matrix &walls) {
   INVARIANT();
   dbc::check(walls[0].size() == $width,
-      fmt::format("Pathing::compute_paths called with walls.width={} but paths $width={}", walls[0].size(), $width));
+      $F("Pathing::compute_paths called with walls.width={} but paths $width={}", walls[0].size(), $width));
 
   dbc::check(walls.size() == $height,
-      fmt::format("Pathing::compute_paths called with walls.height={} but paths $height={}", walls[0].size(), $height));
+      $F("Pathing::compute_paths called with walls.height={} but paths $height={}", walls[0].size(), $height));
 
   // Initialize the new array with every pixel at limit distance
   matrix::assign($paths, WALL_PATH_LIMIT);

src/algos/stats.cpp

@@ -4,7 +4,7 @@
 
 void Stats::dump(std::string msg)
 {
-  dbc::log(fmt::format("{}: sum: {}, sumsq: {}, n: {}, "
+  dbc::log($F("{}: sum: {}, sumsq: {}, n: {}, "
             "min: {}, max: {}, mean: {}, stddev: {}",
             msg, sum, sumsq, n, min, max, mean(),
             stddev()));