+# https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B#Internal_version_numbering
+my $cctype = $ARGS{CCTYPE} =~ s/MSVC//r;
+if ($define{USE_ITHREADS} && ! $define{NO_LOCALE_THREADS}) {
+ $define{USE_LOCALE_THREADS} = 1;
+}
+if (! $define{HAS_SETLOCALE} && $define{HAS_POSIX_2008_LOCALE}) {
+ $define{USE_POSIX_2008_LOCALE} = 1;
+ $define{USE_THREAD_SAFE_LOCALE} = 1;
+}
+elsif ( ($define{USE_LOCALE_THREADS} || $define{USE_THREAD_SAFE_LOCALE})
+ && ( $define{HAS_POSIX_2008_LOCALE}
+ || ($ARGS{PLATFORM} eq 'win32' && ( $cctype !~ /\D/
+ && $cctype >= 80)))
+ && ! $define{NO_THREAD_SAFE_LOCALE})
+{
+ $define{USE_THREAD_SAFE_LOCALE} = 1 unless $define{USE_THREAD_SAFE_LOCALE};
+ $define{USE_POSIX_2008_LOCALE} = 1 if $define{HAS_POSIX_2008_LOCALE};
+}
+
+if ( $ARGS{PLATFORM} eq 'win32'
+ && $define{USE_THREAD_SAFE_LOCALE}
+ && $cctype < 140)
+{
+ $define{TS_W32_BROKEN_LOCALECONV} = 1;
+}
+