-// check if to use precompiled headers
-#if (defined(__BORLANDC__) || defined(__VISUALC__) || defined(__WATCOMC__)) && defined(__WXMSW__)
+// check if to use precompiled headers: do it for most Windows compilers unless
+// explicitly disabled by defining NOPCH
+#if ((defined(__BORLANDC__) || defined(__VISUALC__) || defined(__WATCOMC__)) && defined(__WXMSW__)) || defined(__VISAGECPP__)