Merge branch 'v0.20.x'

src/Main.cxx

@@ -120,8 +120,16 @@ static constexpr size_t KILOBYTE = 1024;
 static constexpr size_t MEGABYTE = 1024 * KILOBYTE;
 
 static constexpr size_t DEFAULT_BUFFER_SIZE = 4 * MEGABYTE;
-static constexpr size_t MIN_BUFFER_SIZE = std::max(CHUNK_SIZE * 32,
-						   64 * KILOBYTE);
+
+static
+#if GCC_OLDER_THAN(5,0)
+/* gcc 4.x has no "constexpr" for std::max() */
+const
+#else
+constexpr
+#endif
+size_t MIN_BUFFER_SIZE = std::max(CHUNK_SIZE * 32,
+				  64 * KILOBYTE);
 
 static constexpr unsigned DEFAULT_BUFFER_BEFORE_PLAY = 10;