introducing const where it might make some sense

config.def.h

@@ -1,8 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 
 /* appearance */
-#define SHOWBAR                       True      /* False means no bar */
-#define TOPBAR                        True      /* False means bottom bar */
 static const char font[]            = "-*-*-medium-*-*-*-14-*-*-*-*-*-*-*";
 static const char normbordercolor[] = "#cccccc";
 static const char normbgcolor[]     = "#cccccc";
@@ -10,8 +8,10 @@ static const char normfgcolor[]     = "#000000";
 static const char selbordercolor[]  = "#0066ff";
 static const char selbgcolor[]      = "#0066ff";
 static const char selfgcolor[]      = "#ffffff";
-static unsigned int borderpx        = 1;        /* border pixel of windows */
-static unsigned int snap            = 32;       /* snap pixel */
+static const unsigned int borderpx  = 1;        /* border pixel of windows */
+static const unsigned int snap      = 32;       /* snap pixel */
+static const Bool showbar           = True;     /* False means no bar */
+static const Bool topbar            = True;     /* False means bottom bar */
 
 /* monitor(s) symbols */
 static const char *monsyms[] = { "<1>", "<2>", "<3>", "<4>", "<5>" };
@@ -19,18 +19,17 @@ static const char *monsyms[] = { "<1>", "<2>", "<3>", "<4>", "<5>" };
 /* tagging */
 static const char *tags[] = { "1", "2", "3", "4", "5", "6", "7", "8", "9" };
 
-static Rule rules[] = {
+static const Rule rules[] = {
 	/* class      instance    title       tags mask     isfloating */
 	{ "Gimp",     NULL,       NULL,       0,            True },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       False },
-
 };
 
 /* layout(s) */
-static float mfact      = 0.55; /* factor of master area size [0.05..0.95] */
-static Bool resizehints = True; /* False means respect size hints in tiled resizals */
+static const float mfact      = 0.55; /* factor of master area size [0.05..0.95] */
+static const Bool resizehints = True; /* False means respect size hints in tiled resizals */
 
-static Layout layouts[] = {
+static const Layout layouts[] = {
 	/* symbol     arrange function */
 	{ "[]=",      tile },    /* first entry is default */
 	{ "><>",      NULL },    /* no layout function means floating behavior */

dwm.c

@@ -66,7 +66,7 @@ typedef union {
 	int i;
 	unsigned int ui;
 	float f;
-	void *v;
+	const void *v;
 } Arg;
 
 typedef struct {
@@ -136,7 +136,7 @@ struct Monitor {
 	Client *stack;
 	Monitor *next;
 	Window barwin;
-	Layout *lt[2];
+	const Layout *lt[2];
 };
 
 typedef struct {
@@ -275,7 +275,7 @@ struct NumTags { char limitexceeded[sizeof(unsigned int) * 8 < LENGTH(tags) ? -1
 void
 applyrules(Client *c) {
 	unsigned int i;
-	Rule *r;
+	const Rule *r;
 	XClassHint ch = { 0 };
 
 	/* rule matching */
@@ -1726,8 +1726,8 @@ updategeom(void) {
 		m->sellt = 0;
 		m->tagset[0] = m->tagset[1] = 1;
 		m->mfact = mfact;
-		m->showbar = SHOWBAR;
-		m->topbar = TOPBAR;
+		m->showbar = showbar;
+		m->topbar = topbar;
 		m->lt[0] = &layouts[0];
 		m->lt[1] = &layouts[1 % LENGTH(layouts)];
 		updatebarpos(m);