X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/ad0cb80ebff7603232ec1621d9b6cfa1ea3471f6..d6b51bdf75f6c7eefae99d73fdd701febeb04db1:/include/xbt/string.hpp

diff --git a/include/xbt/string.hpp b/include/xbt/string.hpp
index 30d6737a70..be542c0914 100644
--- a/include/xbt/string.hpp
+++ b/include/xbt/string.hpp
@@ -4,23 +4,31 @@
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-#ifndef SIMGRIC_XBT_STRING_HPP
-#define SIMGRIC_XBT_STRING_HPP
+#ifndef SIMGRID_XBT_STRING_HPP
+#define SIMGRID_XBT_STRING_HPP
 
-#ifdef HAVE_MC
+#include <simgrid_config.h>
+
+#include <string>
+#include <cstdarg>
+
+#if HAVE_MC
 
 #include <stdexcept>
 #include <cstddef>
 #include <cstdlib>
 #include <cstring>
-#include <string>
 #include <iterator>
 
 #include <xbt/sysdep.h>
 
+#endif
+
 namespace simgrid {
 namespace xbt {
 
+#if HAVE_MC
+
 /** POD structure representation of a string
  */
 struct string_data {
@@ -30,10 +38,21 @@ struct string_data {
 
 /** A std::string with well-known representation
  *
- *  This is a (incomplete) drop-in replacement for std::string.
+ *  This is a (incomplete) drop-in replacement for `std::string`.
+ *  It has a fixed POD representation (`simgrid::xbt::string_data`)
+ *  which can be used to easily read the string content from another
+ *  process.
+ *
+ *  The internal representation of a `std::string` is private.
+ *  We could add some code to read this for a given implementation.
+ *  However, even if we focus on GNU libstdc++ with Itanium ABI
+ *  GNU libstdc++ currently has two different ABIs
  *
- *  This is used for cross-process access to strings
- *  (when the MC is enabled).
+ *  * the pre-C++11 is a pointer to a ref-counted
+ *    string-representation (with support for COW);
+ *
+ *  * the [C++11-conforming implementation](https://gcc.gnu.org/gcc-5/changes.html)
+ *    does not use refcouting/COW but has a small string optimization.
  */
 XBT_PUBLIC_CLASS string : private string_data {
   static const char NUL;
@@ -268,21 +287,16 @@ bool operator>=(std::string const& a, string const& b)
   return b <= a;
 }
 
-}
-}
-
 #else
 
-#include <string>
+typedef std::string string;
 
-namespace simgrid {
-namespace xbt {
+#endif
 
-typedef std::string string;
+std::string string_vprintf(const char *fmt, va_list ap);
+std::string string_printf(const char *fmt, ...);
 
 }
 }
 
 #endif
-
-#endif
\ No newline at end of file