error C2668: ambiguous call to overloaded function

[JHershkowitz]

I am trying to build this in studio 2005, and getting the following error:
error C2668: 'compare_string' : ambiguous call to overloaded function

I am still learning C++, and dont understand the corrections and help others have provided here and other sites for this error. Any help would be great!


From what i can tell, the error occurs in the ContainsSequence function, when it calls the compare_string function


Code:

#include "stdafx.h"

using std::string;


static char SubKeyPath[]=REG_CONFIG_PATH;



int compare_string(const std::string & s1, const std::string& s2)
{
std::string::const_iterator it1=s1.begin();
std::string::const_iterator it2=s2.begin();

//stop when either string's end has been reached
while ( (it1!=s1.end()) && (it2!=s2.end()) )
{
if(::toupper(*it1) != ::toupper(*it2)) // letters differ?
// return -1 to indicate smaller than, 1 otherwise
return (::toupper(*it1) < ::toupper(*it2)) ? -1 : 1;
//proceed to the next character in each string
++it1;
++it2;
}
size_t size1=s1.size(), size2=s2.size();// cache lengths
//return -1,0 or 1 according to strings' lengths
if (size1==size2)
return 0;
return (size1<size2) ? -1 : 1;
}



/*
Function: ContainsSequence
Purpose: Returns true if the password contains a common keyboard sequence
or the reverse of a common keyboard sequence
Notes: this may be obsolete if we just include these sequences in our dictionary
*/

bool ContainsSequence(const char *password, const char *reversepassword) {


//array of keyboard sequences
static char *sequence_array[] = {
"aaaaaa"
//"aaaa",
//"2345",
//"90-="
};

//number of elements in our array
int array_count = sizeof(sequence_array)/sizeof(char *);

bool val;
val = false;

//loop through these sequences and see if they're anywhere in
//our password
for (int z=0;z<array_count; z++) {

//check forward and reverse
//if (strstr(password,sequence_array[z]) || strstr(reversepassword,sequence_array[z])) {
//if (((compare_string(password,sequence_array[z]))==0) || ((compare_string(reversepassword,sequence_array[z]))==0)) {
if ((compare_string(password,sequence_array[z]))==0) {


val = true;
}
}

return val;


}







/*
Function: checkForSequences
Purpose: Returns true or false depending on whether or not we want
to check for keyboard sequences using ContainsSequences
*/



bool checkForSequences()
{
HKEY hConfig;
DWORD dwType, dwLen, checkSequences;
checkSequences = NULL;
bool bVal;
bVal = true;

LONG regOpenStatus = ERROR_SUCCESS;

regOpenStatus = RegOpenKeyEx(HKEY_LOCAL_MACHINE,SubKeyPath,0,KEY_QUERY_VALUE,&hConfig);


if (regOpenStatus == ERROR_SUCCESS) {

// returns the correct dwLen value
RegQueryValueEx(hConfig,CHECK_SEQUENCES_REG_NAME, NULL, &dwType,NULL, &dwLen);

// now call it again to get the DWORD value
if (RegQueryValueEx(hConfig,CHECK_SEQUENCES_REG_NAME, NULL, &dwType,(LPBYTE)&checkSequences, &dwLen) == ERROR_SUCCESS) {

if (dwType == REG_DWORD) {


if (checkSequences == 0) {
bVal = false;
}
}
}


RegCloseKey(hConfig);

}


return bVal;
}

[D_Drmmr]

Please put [code][/code] tags around your code and make sure it's indented correctly. It's very hard to read now.
Also, are there more lines below the compiler error? I would expect something like "could be ... or ... or ...".

[Lindley]

Your code is a rather odd mishmash of C and C++ styles. If you want a case-invariant compare in the C style, use stricmp() or write it if your compiler doesn't have that one (not all of them do).

If you want to use C++ style, use std::strings everywhere rather than relying on char*s, and use std::transform to create lowercase versions.