space character bug using vectors

sanzilla (59)
hi all ,as I know the C++ line spaces and the tab characters and the comments are
dropped out when it passing the C++ lexer state on typical C++ compiler.

But in the visual studio C++ 6.0 The things not work always like this to me . I don't know where is the bug. But what I find is when I drop a line space it given errors.

Compile error source code.
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#include <vector>
#include <iostream>
using namespace std ;

using std::vector;



int main ()
{
	// Declare size of two dimensional array and initialize
	vector<vector<int>> vI2Matrix(3,vector<int>(2,0));
  
	
	
	vI2Matrix[0][0] = 0 ;
	vI2Matrix[0][1] = 1 ;
	vI2Matrix[1][0] = 10 ;
	vI2Matrix[1][1]= 11 ;
	vI2Matrix[2][0] = 20 ;
	vI2Matrix[2][1] = 21;

	cout << "Loop by index :" << endl ;

	int ii , jj ;
	for ( ii = 0 ; ii < 3 ; ii++)
	{
		for ( jj=0 ; jj < 2 ; jj++)
		{
			cout << vI2Matrix[ii][jj] << endl ;
		}
	}
	
	return 0;
}



The corrected source code. see the line space on the 
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#include <vector>
#include <iostream>
using namespace std ;

using std::vector;



int main ()
{
	// Declare size of two dimensional array and initialize
	vector<vector<int> > vI2Matrix(3,vector<int>(2,0));
  
	
	
	vI2Matrix[0][0] = 0 ;
	vI2Matrix[0][1] = 1 ;
	vI2Matrix[1][0] = 10 ;
	vI2Matrix[1][1]= 11 ;
	vI2Matrix[2][0] = 20 ;
	vI2Matrix[2][1] = 21;

	cout << "Loop by index :" << endl ;

	int ii , jj ;
	for ( ii = 0 ; ii < 3 ; ii++)
	{
		for ( jj=0 ; jj < 2 ; jj++)
		{
			cout << vI2Matrix[ii][jj] << endl ;
		}
	}
	
	return 0;
}


see the difference ,

vector<vector<int>> vI2Matrix(3,vector<int>(2,0));

vector<vector<int> > vI2Matrix(3,vector<int>(2,0));

on the line two there is a additional space between the > and > . see it.

the line one gives a compile time error, but the line 2 compiles successfully.
But the problem is , can anybody show me the difference between the line 2 and line 1.
I'm confused . May be this will be working proper on the Dev C++ , ( gnu C++ gcc). Please use the visual C++ 6.0 to regenerate this bug ,may be the latest versions are fixed this bug.
Last edited on
jsmith (5804)
Some older compilers do not handle the ambiguity of >> correctly.

>> is the right-shift operator.

Hence the space is needed to resolve the ambiguity.
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