2023 day 5: add note about an unnecessary-looking copy

yut23 · Jan 24, 2024 · f17eecb · f17eecb
1 parent 2800793
commit f17eecb
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/2023/src/day05.cpp b/2023/src/day05.cpp
@@ -87,6 +87,7 @@ int main(int argc, char **argv) {
         std::size_t N = map.entries.size();
         long curr = 0;
         for (std::size_t i = 0; i < N; ++i) {
+            // make a copy here, as emplace_back can invalidate a reference
             const auto entry = map.entries[i];
             if (curr < entry.start) {
                 map.entries.emplace_back(curr, curr, entry.start - curr);