[Dev-C++] Errors: template-id in the declaration of primary template

[Edward H. <hyl...@gm...>]

hi,everyone.  today, i wrote a program to test the function template.
When i complided the program, it gave the errrors:
      spec.cpp:19: template-id `bytes<wchar_t*>' in declaration of
primary template.

After searching the network, i have no idea about this error.

my g++ version is 3.22

the source code is here:
//: spec.cpp
#include<iostream>
#include<string.h>
#include<string>

using namespace std;

template<class T>
size_t bytes(T& t){
        cout << "(using primary template)\n";
        return sizeof t;
}

size_t bytes(char*& s){
        cout << "using char* overload)\n";
        return strlen(s) + 1;
}

size_t bytes<wchar_t *>(wchar_t*& w){
        cout << "(using wchar_t* specialization)\n";
        return 2*(wcslen(w)+1);
}

}

template<>
size_t bytes<>(string& s){
        cout << "(using string explicit specialization)\n";
        return sizeof s;
}

template<>
size_t bytes<float>(float& x){
        cout << "(using float specialization)\n";
        return sizeof x;
}


int main(){
        int i;
        cout << "bytes in i: " << bytes(i) << endl;
        char *s = "hello";
        cout << "bytes in s: " << bytes(s) << endl;
        wchar_t *w = L"goodbye";
        cout << "bytes in w: " << bytes(w) << endl;
        string t;
        cout << "bytes in w: " << bytes(w) << endl;
        string t;
        cout << "bytes in t: " << bytes(t) << endl;
        float x;
        cout << "bytes in x: " << bytes(x) << endl;
        double y;
        cout << "bytes in y: " << bytes(y) << endl;
        return 0;
}
~


thanks for your help!