From 6d60c710747cbee755b9f50d88ee7c71096a289f Mon Sep 17 00:00:00 2001
From: WormHeamer
Date: Fri, 2 Jan 2026 19:34:24 -0500
Subject: try to concatenate strings in-place when possible

---
 arena.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

(limited to 'arena.h')

diff --git a/arena.h b/arena.h
index 1be5cd7..5235204 100644
--- a/arena.h
+++ b/arena.h
@@ -24,6 +24,7 @@ void arena_free(Arena *a);
 void arena_reset(Arena *a);
 void *arena_alloc(Arena *a, size_t n, size_t align);
 void *arena_realloc(Arena *a, void *old, size_t oldsz, size_t newsz, size_t align);
+void *arena_concat(Arena *m, void *a, size_t asz, void *b, size_t bsz, size_t align);
 
 #define new(a, t)\
     memset(arena_alloc(a, sizeof(t), _Alignof(__typeof__(t))), 0, sizeof(t))
@@ -89,5 +90,15 @@ void *arena_realloc(Arena *a, void *old, size_t oldsz, size_t newsz, size_t alig
 	}
 }
 
+void *arena_concat(Arena *m, void *a, size_t asz, void *b, size_t bsz, size_t align) {
+	if (!asz)
+		return b;
+	if (!bsz || (char*)a + asz == b)
+		return a;
+	void *p = arena_realloc(m, a, asz, asz + bsz, align);
+	memcpy((char*)p + asz, b, bsz);
+	return p;
+}
+
 #endif
 #endif
-- 
cgit v1.2.3