Thread: Help filling a structure with data from a file.

>It was this code, wasn't it
Yes, I'm getting this error: no matching function for call to `std::bad_cast::bad_cast(const char[19])'

bad_cast seems to exist, because it says: candidates are

Which line? I'm rather confused!!

With this code -

Code:

#include <algorithm>
#include <iostream>
#include <vector>
#include <fstream>
#include <sstream>

#include <windows.h>

// Your struct
struct Info
{
	double price;
	int serialNum;
	std::string descript;
	int order;
};

// Templated type-cast function
template <typename T, typename U>
T lexical_cast ( U src )
{
	std::stringstream s;
	T dst;

	if ( !( s << src ) || !( s >> dst ) )
	throw std::bad_cast ( "Invalid conversion" );

	return dst;
}


int main ( void )
{
	std::ifstream in ( "thing.txt" );

	if ( !in ) 
	{
		in.close();

		return 1;
	}

	std::string temp;
	Info info;

	while ( getline( in, temp, ',' ) )
	{
		info.price = lexical_cast< double, std::string > ( temp );
		std::cout<< '\n' << "Price: " << info.price;

		getline( in, temp, ',' );
		info.serialNum = lexical_cast< int, std::string > ( temp );
		std::cout<< '\n' << "Serial: " << info.serialNum;

		getline( in, temp, ',' );
		info.descript = temp;
		std::cout<< '\n' << "Description: " << info.descript;

		getline( in, temp, '\n' );
		info.order = lexical_cast< int, std::string > ( temp );
		std::cout<< '\n' << "Order #: " << info.order << '\n';
	}

	in.close();

	return 0;
}

code, I get this result -

Attachment 6811

from this text file -

253.99,4478,Video Card,1
88.99,7789,Motherboard,3
154.99,4753,CPU,2

Limitations - just one info variable, not an array.

>> std::bad_cast ( "Invalid conversion" );
This is non-standard (18.5.2). There is no bad_cast constructor that takes a string (C or C++ style). Some implementations might allow it.

>This is non-standard (18.5.2). There is no bad_cast constructor that takes a string (C or C++ style).
Is there any way to rewrite that line? The compiler shows a candidate with a bad_cast as the argument:
C:/program files/Dev-Cpp/include/c++/3.3.1/typeinfo:136: error: candidates are:
std::bad_cast::bad_cast(const std::bad_cast&)

I'll post the line so others readers know.

Code:

	throw std::bad_cast ( "Invalid conversion" );

Originally Posted by twomers

Just get rid of that line It should work without it. It's the throw line, right?

Yes, the throw line. Or I suppose I could change it to some other std::exception.

>Does it work without the exception?
Yes.

>or just throw a bad_cast without any error message (throw std::bad_cast();).
Ok, I did this, and the code now compiles and runs.