externals: Add fmt subtree

Merge commit 'a9f62a15cd' as 'externals/fmt'

externals/fmt/test/util.cc

@@ -0,0 +1,64 @@
+/*
+ Test utilities.
+
+ Copyright (c) 2012-2014, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "util.h"
+#include <cstring>
+
+void increment(char *s) {
+  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
+    if (s[i] != '9') {
+      ++s[i];
+      break;
+    }
+    s[i] = '0';
+  }
+}
+
+std::string get_system_error(int error_code) {
+#if defined(__MINGW32__) || !defined(_WIN32)
+  return strerror(error_code);
+#else
+  enum { BUFFER_SIZE = 200 };
+  char buffer[BUFFER_SIZE];
+  if (strerror_s(buffer, BUFFER_SIZE, error_code))
+    throw std::exception("strerror_s failed");
+  return buffer;
+#endif
+}
+
+const char *const FILE_CONTENT = "Don't panic!";
+
+fmt::BufferedFile open_buffered_file(FILE **fp) {
+  fmt::File read_end, write_end;
+  fmt::File::pipe(read_end, write_end);
+  write_end.write(FILE_CONTENT, std::strlen(FILE_CONTENT));
+  write_end.close();
+  fmt::BufferedFile f = read_end.fdopen("r");
+  if (fp)
+    *fp = f.get();
+  return f;
+}