source/include/autosprintf.h

0001 /* Class autosprintf - formatted output to an ostream.
0002    Copyright (C) 2002, 2012-2016 Free Software Foundation, Inc.
0003
0004    This program is free software: you can redistribute it and/or modify
0005    it under the terms of the GNU Lesser General Public License as published by
0006    the Free Software Foundation; either version 2.1 of the License, or
0007    (at your option) any later version.
0008
0009    This program is distributed in the hope that it will be useful,
0010    but WITHOUT ANY WARRANTY; without even the implied warranty of
0011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0012    GNU Lesser General Public License for more details.
0013
0014    You should have received a copy of the GNU Lesser General Public License
0015    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
0016
0017 #ifndef _AUTOSPRINTF_H
0018 #define _AUTOSPRINTF_H
0019
0020 /* This feature is available in gcc versions 2.5 and later.  */
0021 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
0022 # define _AUTOSPRINTF_ATTRIBUTE_FORMAT() /* empty */
0023 #else
0024 /* The __-protected variants of 'format' and 'printf' attributes
0025    are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
0026 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
0027 #  define _AUTOSPRINTF_ATTRIBUTE_FORMAT() \
0028   __attribute__ ((__format__ (__printf__, 2, 3)))
0029 # else
0030 #  define _AUTOSPRINTF_ATTRIBUTE_FORMAT() \
0031   __attribute__ ((format (printf, 2, 3)))
0032 # endif
0033 #endif
0034
0035 #include <string>
0036 #include <iostream>
0037
0038 namespace gnu
0039 {
0040   /* A temporary object, usually allocated on the stack, representing
0041      the result of an asprintf() call.  */
0042   class autosprintf
0043   {
0044   public:
0045     /* Constructor: takes a format string and the printf arguments.  */
0046     autosprintf (const char *format, ...)
0047                 _AUTOSPRINTF_ATTRIBUTE_FORMAT();
0048     /* Copy constructor.  */
0049     autosprintf (const autosprintf& src);
0050     /* Assignment operator.  */
0051     autosprintf& operator = (autosprintf temporary);
0052     /* Destructor: frees the temporarily allocated string.  */
0053     ~autosprintf ();
0054     /* Conversion to string.  */
0055     operator char * () const;
0056     operator std::string () const;
0057     /* Output to an ostream.  */
0058     friend inline std::ostream& operator<< (std::ostream& stream, const autosprintf& tmp)
0059     {
0060       stream << (tmp.str ? tmp.str : "(error in autosprintf)");
0061       return stream;
0062     }
0063   private:
0064     char *str;
0065   };
0066 }
0067
0068 #endif /* _AUTOSPRINTF_H */