Catch a throw exception with a custom string parameter - c++

Question

I'm trying to implement something similar to the following in my VS 2008 C++/MFC project:
class myClass()
{
public:
myClass()
{
//Do work... check for errors
if(var < 0)
{
//Error
TCHAR buff[1024];
_snwprintf_s(buff, SIZEOF(buff), L"ERROR: The value of var=%d", var);
throw buff;
}
}
};
__try
{
//Begin using class above
//The class member may be also defined on the global scale, thus
//the following exception trap may happen via SetUnhandledExceptionFilter
myClass mc;
}
__except(1)
{
//Process unhandled exception
//But how to trap the string passed in 'throw' above?
}
But I can't seem to catch the "string" that I'm passing in the throw statement.

Answer 1

Use std::runtime_error, eg:
#include <stdexcept>
class myClass()
{
public:
myClass()
{
//Do work...check for errors
if(var < 0)
{
//Error
char buff[1024];
_snprintf_s(buff, SIZEOF(buff), "ERROR: The value of var=%d", var);
throw std::runtime_error(buff);
}
}
};
try
{
//Begin using class above
myClass mc;
}
catch (const std::runtime_error &e)
{
//Process unhandled exception
//e.what() will return the string message ...
}

Answer 2

You can try something like this, for example:
struct CustomError {
CustomError(std::string& info)
: m_info(info) {}
std::string m_info;
};
/*...*/
int main() {
try {
std::string info = "yo dawg";
throw CustomError(info);
}
catch (CustomError& err) {
std::cout << "Error:" << err.m_info;
}
}

Answer 3

Character buffer way:
#include <string>
#include <iostream>
void DoSomething()
{
throw "An error occurred!";
}
int main()
{
try
{
DoSomething();
std::cout << "Nothing bad happened" << std:endl;
}
catch(const char &err)
{
std::cerr << err << std::endl;
}
}
, or std::string way:
#include <string>
#include <iostream>
void DoSomething()
{
throw std::string("An error occurred!");
}
int main()
{
try
{
DoSomething();
std::cout << "Nothing bad happened" << std:endl;
}
catch(std::string &err)
{
std::cerr << err << std::endl;
}
}