tests: c++: fix symbol lookup issue

Sun C 5.13 SunOS_sparc 2014/10/20 reports errors on tests 430-432.

Reported by Dennis Clarke.
<http://lists.gnu.org/archive/html/bug-bison/2015-01/msg00087.html>

* tests/c++.at (Variants): Be sure to emit operator<< before using it:
use "%code top" rather than "%code".
Prefer std::vector to std::list.
Do not define anything in std::, to avoid undefined behavior.

tests/c++.at

@@ -96,7 +96,7 @@ AT_SETUP([C++ Variant-based Symbols])
 AT_KEYWORDS([variant])
 
 AT_BISON_OPTION_PUSHDEFS([%skeleton "lalr1.cc" %debug $1])
-# Store strings and integers in a list of strings.
+# Store strings and integers in a vector of strings.
 AT_DATA_GRAMMAR([list.y],
 [[%skeleton "lalr1.cc"
 %define api.value.type variant
@@ -114,20 +114,20 @@ AT_DATA_GRAMMAR([list.y],
 }
 
 %token <int> INT "int"
-%type < std::list<int> > exp
+%type < std::vector<int> > exp
 
 %printer { yyo << $$; } <int>
 %printer
   {
-    for (std::list<int>::const_iterator i = $$.begin (); i != $$.end (); ++i)
+    for (std::vector<int>::const_iterator i = $$.begin (); i != $$.end (); ++i)
       {
         if (i != $$.begin ())
           yyo << ", ";
         yyo << *i;
       }
-  } < std::list<int> >
+  } < std::vector<int> >
 
-%code requires { #include <list> }
+%code requires { #include <vector> }
 %code { int yylex (yy::parser::semantic_type* yylval); }
 
 %%
@@ -185,7 +185,7 @@ m4_pushdef([AT_TEST],
 [AT_SETUP([Variants $1])
 
 AT_BISON_OPTION_PUSHDEFS([%debug $1])
-# Store strings and integers in a list of strings.
+# Store strings and integers in a vector of strings.
 AT_DATA_GRAMMAR([list.y],
 [[%debug
 %define api.value.type variant
@@ -194,29 +194,25 @@ AT_DATA_GRAMMAR([list.y],
 
 %code requires // code for the .hh file
 {
-#include <list>
+#include <vector>
 #include <string>
-typedef std::list<std::string> strings_type;
+typedef std::vector<std::string> strings_type;
 }
 
-%code // code for the .cc file
+%code top // code for the .cc file.
 {
 #include <cstdlib> // abort, getenv
 #include <iostream>
+#include <vector>
 #include <sstream>
+#include <string>
+
+
+  typedef std::vector<std::string> strings_type;
 
   namespace yy
   {
-    static]AT_TOKEN_CTOR_IF([[
+    // Must be available early, as is used in %destructor.
-    parser::symbol_type yylex ()]], [[
-    parser::token_type yylex (parser::semantic_type* yylval]AT_LOCATION_IF([,
-                              parser::location_type* yylloc])[)]])[;
-  }
-
-  // Printing a list of strings (for %printer).
-  // Koening look up will look into std, since that's an std::list.
-  namespace std
-  {
     std::ostream&
     operator<<(std::ostream& o, const strings_type& s)
     {
@@ -230,16 +226,27 @@ typedef std::list<std::string> strings_type;
       return o << ')';
     }
   }
+}
 
-  // Conversion to string.
+%code // code for the .cc file.
-  template <typename T>
+{
-    inline
+  namespace yy
-    std::string
-    to_string (const T& t)
   {
-    std::ostringstream o;
+    static]AT_TOKEN_CTOR_IF([[
-    o << t;
+    parser::symbol_type yylex ()]], [[
-    return o.str ();
+    parser::token_type yylex (parser::semantic_type* yylval]AT_LOCATION_IF([,
+                              parser::location_type* yylloc])[)]])[;
+
+    // Conversion to string.
+    template <typename T>
+      inline
+      std::string
+      to_string (const T& t)
+    {
+      std::ostringstream o;
+      o << t;
+      return o.str ();
+    }
   }
 }
 
@@ -252,10 +259,10 @@ typedef std::list<std::string> strings_type;
 // Using the template type to exercize its parsing.
 // Starting with :: to ensure we don't output "<::" which starts by the
 // digraph for the left square bracket.
-%type <::std::list<std::string>> list;
+%type <::std::vector<std::string>> list;
 
 %printer { yyo << $$; }
-  <int> <::std::string> <::std::list<std::string>>;
+  <int> <::std::string> <::std::vector<std::string>>;
 %destructor { std::cerr << "Destroy: " << $$ << '\n'; } <*>;
 %destructor { std::cerr << "Destroy: \"" << $$ << "\"\n"; } <::std::string>;
 %%