string.find function returning odd numbers - c++

Question

I am trying to find the position at which a character was found.
const char* normalize(std::string path)
{
std::cout << "executed " << path << std::endl;
//"foo//\\\bar////bar2///../.\bar2" -- foo/bar/bar2
std::size_t found;
std::size_t found2;
std::size_t curchar = 0;
std::string final;
std::string buffer;
bool notdone = true;
while (notdone) {
//std::cout << "loop" << std::endl;
//find the current element
// can be / or \
found = path.find("/", curchar);
found2 = path.find("\\",curchar);
std::cout << found << std::endl;
SDL_Delay(2000);
if (found != std::string::npos && found2 != std::string::npos) {
if (found < found2){
//read from the curchar to the slash
if (curchar-found > 1){
buffer = path.substr(curchar,found-curchar-1);
//add to path
final = final + "/" + buffer;
}
curchar = found+1;
//buffer will be the file/component
}else{
if (curchar-found2 > 1){
buffer = path.substr(curchar,found2-curchar-1);
//add to path
final = final + "/" + buffer;
}
curchar = found2+1;
}
}else if(found != std::string::npos){
//std::cout << "loop2" << found == std::string::npos << std::endl;
//std::cout << "loop2 " << path.substr(curchar, 1) << std::endl;
if (curchar-found > 1){//
buffer = path.substr(curchar,found-curchar-1);
//add to path
final = final + "/" + buffer;
}
curchar = found+1;
}else if(found2 != std::string::npos){
std::cout << "loop3" << std::endl;
if (curchar-found2 > 1){
buffer = path.substr(curchar,found2-curchar-1);
//add to path
final = final + "/" + buffer;
}
curchar = found2+1;
}else{
std::cout << "finishing" << std::endl;
final = final + "/" + path.substr(curchar,path.size()-curchar);
notdone = false;
}
}
return final.c_str();
}
normalize("test/");
This code should print out '4', but it instead prints out 18. It prints out 18 in an infinite loop. However, if I use std::cout << path.find("/", curchar) << std::endl it does print 4. At first I thought that it wasn't actually returning std::size_t but I checked and it was.

Answer 1

Your following line is creating the problem
//find the current element
// can be / or \
found = path.find("/", curchar);
I ran on my linux terminal and GCC treated as next line as continuation of comment of above line.
basic.cpp:18:9: warning: multi-line comment [-Wcomment]
// can be / or \
^
basic.cpp: In function ‘const char* normalize(std::string)’:
basic.cpp:21:22: warning: ‘found’ may be used uninitialized in this function [-Wmaybe-uninitialized]
std::cout << found << std::endl;
^
Now due to above comment style, your next line(code) was treated as comment. As found was not initialized so it had garbage value which screwed up your logic as it did not go inside the path where you have reset the flag notdone.
However GCC or any other compiler should give warning(usage of uninitialize variable) and if we would have carefully read, we might have back-trace and understood the problem.
Solution for this would be to change the comment style as
/* // can be / or \ */