hash_set was not declared even I #include<hash_set>

Dear advanced c/g++ programers:
  I tried the following code
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// Example 6-8 Storing strings in a hast_set
#include <iostream>
#include <string>
#include <hash_set>
using namespace std;

int main() {

  hash_set<std::string> hsString;
  string s = "bravo";

  hsString.insert(s);
  s = "alpha";
  hsString.insert(s);
  s = "charlie";
  hsString.insert(s);

  for (hash_set<string>::const_iterator p = hsString.begin();
       p != hsString.end(); ++p)
     cout << *p << endl; // Note that these aren't guaranteed
                // to be in sorted order
}
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but I got the following compile error(g++ 4.5.2)
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eric@eric-laptop:~/cppcookbook/ch6$ g++ -Wno-deprecated Example6-8.cpp
Example6-8.cpp: In function =91int main()':
Example6-8.cpp:9:3: error: =91hash_set' was not declared in this scope
Example6-8.cpp:9:23: error: expected primary-expression before =91>'
token
Example6-8.cpp:9:25: error: =91hsString' was not declared in this scope
Example6-8.cpp:18:23: error: expected primary-expression before =91>'
token
Example6-8.cpp:18:24: error: =91::const_iterator' has not been declared
Example6-8.cpp:18:41: error: expected =91;' before =91p'
Example6-8.cpp:19:8: error: =91p' was not declared in this scope
eric@eric-laptop:~/cppcookbook/ch6$
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your can get the code to test by yourself
source code
http://examples.oreilly.com/9780596007614/

Thanks your help a lot in advance, Eric