Allow use of inline keyword in c++/c99 mode
diff --git a/brotli/dec/types.h b/brotli/dec/types.h
index bc09f8b..2f79b2a 100644
--- a/brotli/dec/types.h
+++ b/brotli/dec/types.h
@@ -22,10 +22,11 @@
 
 #ifndef _MSC_VER
 #include <inttypes.h>
-#ifdef __STRICT_ANSI__
-#define BROTLI_INLINE
-#else  /* __STRICT_ANSI__ */
+#if defined(__cplusplus) || !defined(__STRICT_ANSI__) \
+    || __STDC_VERSION__ >= 199901L
 #define BROTLI_INLINE inline
+#else
+#define BROTLI_INLINE
 #endif
 #else
 typedef signed   char int8_t;