diff --git a/.ccls b/.ccls
new file mode 100644
index 0000000..a6dc4f8
--- /dev/null
+++ b/.ccls
@@ -0,0 +1,2 @@
+clang++
+%cpp -std=c++20 -D_POSIX_C_SOURCE=199309L -O3 -g -Wall -Wextra -Wno-type-limits