std::search isn't working!

I'm trying to do a case insensitive comparison on two strings. I found this piece of code online but since I've never used std::search before, I don't know how to make the predicate part work. Here's what I've got so far...

Code:

---

bool ci_equal(char ch1, char ch2)
        {
                return toupper((unsigned char)ch1) == toupper((unsigned char)ch2);
        }
       
        size_t ci_find(const string& str1, const string& str2)
        {
                string::const_iterator pos = search(str1.begin( ), str1.end( ), str2.begin( ), str2.end( ), ci_equal());  //PROBLEM IN THIS LINE!
                if (pos == str1.end( ))
                        return string::npos;
                else
                        return pos - str1.begin( );
        }

---

It won't compile. Can anyone tell me how to make this code work?

ci_equal is a function, not a function object, and to pass a pointer to this function, leave out the parenthesis.

Quote:

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Originally Posted by black_spot1984

I'm trying to do a case insensitive comparison on two strings. I found this piece of code online but since I've never used std::search before, I don't know how to make the predicate part work. Here's what I've got so far...

Code:

---

bool ci_equal(char ch1, char ch2)
        {
                return toupper((unsigned char)ch1) == toupper((unsigned char)ch2);
        }
       
        size_t ci_find(const string& str1, const string& str2)
        {
                string::const_iterator pos = search(str1.begin( ), str1.end( ), str2.begin( ), str2.end( ), ci_equal() );  //PROBLEM IN THIS LINE!
                if (pos == str1.end() )
                        return string::npos;
                else
                        return pos - str1.begin( );
        }

---

It won't compile. Can anyone tell me how to make this code work?

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Remove the parentheses.

Thanks for the reply. I changed my code so it looks like:

Code:

---

bool ci_equal(char ch1, char ch2)
        {
                return toupper((unsigned char)ch1) == toupper((unsigned char)ch2);
        }
       
        size_t ci_find(const string& str1, const string& str2)
        {
                string::const_iterator pos = search(str1.begin( ), str1.end( ), str2.begin( ), str2.end( ), ci_equal);
                if (pos == str1.end( ))
                        return string::npos;
                else
                        return pos - str1.begin( );
        }

---

Now I'm getting the error message:

Quote:

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error: no matching function for call to ‘search(__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, <unresolved overloaded function type>)’
/usr/lib/gcc/i386-redhat-linux/4.3.0/../../../../include/c++/4.3.0/bits/stl_algo.h:4123: note: candidates are: _FIter1 std::search(_FIter1, _FIter1, _FIter2, _FIter2, _BinaryPredicate) [with _FIter1 = __gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, _FIter2 = __gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, _BinaryPredicate = bool (webCrawler::*)(char, char)]

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Is ci_equal a member function?

For those who are curious, what I was doing wrong was in the way I was including the two files. It worked when I got them both into the file in the right place.

If you're getting compile errors by switching around the order of your #include statements, then you've got other problems that need fixing.