1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 #ifndef nsPrintfCString_h___
8 #define nsPrintfCString_h___
9 
10 #include "nsString.h"
11 
12 /**
13  * nsPrintfCString lets you create a nsCString using a printf-style format
14  * string.  For example:
15  *
16  *   NS_WARNING(nsPrintfCString("Unexpected value: %f", 13.917).get());
17  *
18  * nsPrintfCString has a small built-in auto-buffer.  For larger strings, it
19  * will allocate on the heap.
20  *
21  * See also nsCString::AppendPrintf().
22  */
23 class nsPrintfCString : public nsFixedCString
24 {
25   typedef nsCString string_type;
26 
27 public:
28   explicit nsPrintfCString(const char_type* aFormat, ...)
29     : nsFixedCString(mLocalBuffer, kLocalBufferSize, 0)
30   {
31     va_list ap;
32     va_start(ap, aFormat);
33     AppendPrintf(aFormat, ap);
34     va_end(ap);
35   }
36 
37 private:
38   static const uint32_t kLocalBufferSize = 16;
39   char_type mLocalBuffer[kLocalBufferSize];
40 };
41 
42 #endif // !defined(nsPrintfCString_h___)
43