1 files changed, 49 insertions, 0 deletions
diff --git a/kit/move_back.h b/kit/move_back.h
new file mode 100644
index 0000000..1885f5d
--- /dev/null
+++ b/kit/move_back.h
@@ -0,0 +1,49 @@
+#ifndef KIT_MOVE_BACK_H
+#define KIT_MOVE_BACK_H
+
+#include "types.h"
+
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define KIT_MOVE_BACK_INL(new_size, array, ...)          \
+  do {                                                   \
+    i64 index_;                                          \
+    i64 end_ = (array).size;                             \
+    u8  temp_[sizeof *(array).values];                   \
+    for (index_ = 0; index_ < end_;) {                   \
+      if (__VA_ARGS__) {                                 \
+        end_--;                                          \
+        if (index_ != end_) {                            \
+          memcpy(temp_, (array).values + end_,           \
+                 sizeof *(array).values);                \
+          (array).values[end_] = (array).values[index_]; \
+          memcpy((array).values + index_, temp_,         \
+                 sizeof *(array).values);                \
+        }                                                \
+      } else                                             \
+        index_++;                                        \
+    }                                                    \
+    (new_size) = end_;                                   \
+  } while (0)
+
+#define KIT_MOVE_BACK(new_size, array, value, cond) \
+  KIT_MOVE_BACK_INL(new_size, array,                \
+                    (cond) ((array).values[index_], (value)))
+
+#define KIT_MOVE_BACK_REF(new_size, array, value, cond) \
+  KIT_MOVE_BACK_INL(new_size, array,                    \
+                    (cond) ((array).values + index_, (value)))
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MOVE_BACK_INL KIT_MOVE_BACK_INL
+#define MOVE_BACK KIT_MOVE_BACK
+#define MOVE_BACK_REF KIT_MOVE_BACK_REF
+
+#endif