Make the code base clean under -Wwrite-strings.

I've also added that warning option and -Werror to the build script,
so that I'll find out if I break this property in future.

1 files changed, 2 insertions, 2 deletions

diff --git a/twiddle.c b/twiddle.c
index fb8f700..1f2825f 100644
--- a/twiddle.c
+++ b/twiddle.c
@@ -80,9 +80,9 @@ static game_params *dup_params(const game_params *params)
 static int game_fetch_preset(int i, char **name, game_params **params)
 {
     static struct {
-        char *title;
+        const char *title;
         game_params params;
-    } presets[] = {
+    } const presets[] = {
         { "3x3 rows only", { 3, 3, 2, TRUE, FALSE } },
         { "3x3 normal", { 3, 3, 2, FALSE, FALSE } },
         { "3x3 orientable", { 3, 3, 2, FALSE, TRUE } },