Add version constraint for building against external library

dopuskh3 · dopuskh3 · commit 3714d97a8784 · 2021-11-23T11:48:45.000+01:00
diff --git a/external_zstd.go b/external_zstd.go
@@ -5,4 +5,10 @@ package zstd
 
 // #cgo CFLAGS: -DUSE_EXTERNAL_ZSTD
 // #cgo pkg-config: libzstd
+/*
+#include<zstd.h>
+#if ZSTD_VERSION_NUMBER < 100400000
+#error "ZSTD version >= 1.4 is required"
+#enif
+*/
 import "C"
