--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/mystring/subst.cc	Wed Jan 16 22:39:43 2008 +0100
@@ -0,0 +1,18 @@
+#include "mystring.h"
+
+mystring mystring::subst(char from, char to) const
+{
+  const unsigned length = rep->length;
+  char buf[length+1];
+  const char* in = rep->buf + length;
+  bool changed = true;
+  for(char* out = buf+length; out >= buf; in--, out--)
+    if(*in == from)
+      *out = to, changed = true;
+    else
+      *out = *in;
+  if(!changed)
+    return *this;
+  else
+    return mystring(buf, length);
+}