add mkstemp implementations for tests on Windows

test/include/win_mkstemp.hpp

@@ -0,0 +1,42 @@
+/*
+ * mkstemp.c
+ *
+ * Provides a trivial replacement for the POSIX `mkstemp()' function,
+ * suitable for use in MinGW (Win32) applications.
+ *
+ * This file is part of the MinGW32 package set.
+ *
+ * Contributed by Keith Marshall <keithmarshall@users.sourceforge.net>
+ * Patched to VS2013 by alex85k
+ * THIS SOFTWARE IS NOT COPYRIGHTED
+ *
+ * This source code is offered for use in the public domain. You may
+ * use, modify or distribute it freely.
+ *
+ * This code is distributed in the hope that it will be useful but
+ * WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
+ * DISCLAIMED. This includes but is not limited to warranties of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#ifndef WIN_MKSTEMP_H
+#define WIN_MKSTEMP_H
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <share.h>
+
+inline int mkstemp( char *templ )
+{
+  int maxtry = 26, rtn = -1;
+
+  while( maxtry-- && (rtn < 0) )
+  {
+    char *r = _mktemp( templ );
+    if( r == NULL )
+      return -1;
+    rtn = sopen( r, O_RDWR | O_CREAT | O_EXCL | O_BINARY, SH_DENYRW, 0600 );
+  }
+  return rtn;
+}
+#endif

test/t/index/test_typed_mmap.cpp

@@ -4,6 +4,10 @@ using boost::test_tools::output_test_stream;
 
 #include <osmium/index/detail/typed_mmap.hpp>
 
+#ifdef _MSC_VER
+  #include "win_mkstemp.hpp"
+#endif
+
 TEST_CASE("TypedMmap") {
 
 SECTION("Mmap") {