Map "find" function wont work.

[Cman87]

Hi,
I have a question that bugs me for days now. I have a piece of code of a map that has a char* for the key. And char* as value. Which looks like

typedef std::map<char*,char*,chchMapComp> chchMap;

And the comparison is done,

struct chchMapComp {
bool operator()(const char *a, const char *b) const {
return std::strcmp( a, b ) < 0;
}
};

When I run the program the data is populated properly. But its when I find for a element that puzzles me.

Initially I compiled the code through Visual Studio. The code worked fine. But when I compiled in Solaris using g++ the map find function didnt work as expected. The code compiles, in both machines. I dont know where I went wrong.

Someone please give me a clue..

[writetonsharma]

I didn't see any such problems when running on solaris.

bash-3.2$ g++ -v
Using built-in specs.
Target: sparc-sun-solaris2.10
Configured with: /gccsrc/gcc-4.1.1/configure --prefix=/usr/local --enable-languages=c,c++
Thread model: posix
gcc version 4.1.1

here is the code I used.

#include<iostream>
#include<fstream>
#include<cstdlib>
#include<cctype>
#include <map>

using namespace std;

struct chchMapComp {
	bool operator()(char *a, char *b) {
		return strcmp( a, b ) < 0;
	}
};


int main()
{

	std::map<char*, char*, chchMapComp> chchMap;

	{
		char* key = "key1";
		char* value = "hello1";
		chchMap.insert(std::pair<char*, char*>(key, value));
	}
	{
		char* key = "key2";
		char* value = "hello2";
		chchMap.insert(std::pair<char*, char*>(key, value));
	}
	
	//chchMap.insert("key3", "hello3");
	//chchMap.insert("key4", "hello4");

	std::map<char*, char*, chchMapComp>::iterator iter = chchMap.find("key1");
	std::cout << iter->second << std::endl;


	return 0;
}

[Cman87]

Thanks alot writetonsharma, the thing is when I hard code the key it gave me the required results. As you have done here.

But when I pass a char* to find method it gave me random results. I checked the value of the passd variable through VS2010 and found that the values are same.

char *val something like "C000003" when I cout in two different instances as shown in code below,

cout<<"--"<<val<<"--"<<endl;

On windows it gave me
--C000003--
but on Solaris
--C000003

As you can see the las two "--" isnt printed. So I had doubts in the char* that I was passing.

[ne555]

¿why don't use a debugger to see the variable?
Probably the problem is in your code, you may post it.

If you are reading from a file, keep in mind the different line terminators
\r\n, \n, \r

[writetonsharma]

as ne555 said, you will have to post more code. It must be in your code only.