[Bug libstdc++/13342] New: hash_map doesn't support std::string keys

["kgirard at connect dot carleton dot ca" <gcc-bugzilla at gcc dot gnu dot org>]

Overview Description:
 The GNU extension hash_map class doesn't support using std::strings for keys. I
think it should support a common class like std::string

Steps to Reproduce:

  I compiled this:

  #include <string>
  #include <ext/hash_map>

  using namespace std;
  using namespace __gnu_cxx;

  int main()
  {
    hash_map<string, int> hm;
    hm["January"] = 30;
    return 0;
  }

  with the following:

  g++ hashtest.cpp


Actual Results:

  Gcc gave me the following error

  ...<snip>....
  /usr/include/c++/3.3/ext/stl_hashtable.h:514: error: no match for call to `(
     const __gnu_cxx::hash<std::string>) (const std::basic_string<char,
     std::char_traits<char>, std::allocator<char> >&)'


Expected Results:

  Successful Compile


Solution:
 
Add

  template<> struct hash<std::string>                                          
            
  {                                                                            
              
    size_t operator()(const std::string& __x) const 
    { 
      return __stl_hash_string(__x.c_str()); 
    }                                                                          
              
  };                                                                           
              

to ext/stl_hash_fun.h

-- 
           Summary: hash_map doesn't support std::string keys
           Product: gcc
           Version: 3.3.3
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kgirard at connect dot carleton dot ca
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13342