Problem while porting from 2008 to 2013

[maverick786us]

I have a source code like this.

std::istringstream i(svalue);
bool converted = (i >> level != 0);

It is working perfectly fine in VS2008. But when I ported it to 2013, I am coming across this error

Error 13 error C2678: binary '!=' : no operator found which takes a left-hand operand of type 'std::basic_istream<char,std::char_traits<char>>' (or there is no acceptable conversion) D:\Archana\Proj - VS2013\GCF03292015\GCF\Source\MadelineDll\DrawingCanvas.cpp 1711 1 MadelineDLL

There is a red underline inside the brackets right underneath the ! for this error. Can someone help me in rectifying this error?

[2kaud]

As bool() operator is defined for stringstream for c++11, try

bool converted = (i >> level);

[maverick786us]

As bool() operator is defined for stringstream for c++11, try

bool converted = (i >> level);

The result is still the same.

This is the error

Error 13 error C2440: 'initializing' : cannot convert from 'std::basic_istream<char,std::char_traits<char>>' to 'bool' D:\Archana\Proj - VS2013\GCF03292015\GCF\Source\MadelineDll\DrawingCanvas.cpp 1711 1 MadelineDLL

[2kaud]

The issue is the assignment. This compiles for MSVS2013

bool converted (i >> level );

For an assignment, you need to cast to bool

bool converted = static_cast<bool>(i >> level );

[superbonzo]

The issue is the assignment

the issue is rather that std::istream declares an explicit operator bool() ( from c++11 on ) that in turn exactly forbids such conversions via copy-initialization ( as explicit constructors do ). Why ? because in this way the standard can define contextual boolean conversions as being equivalent to "bool a(b);" hence disallowing unwanted or dangerous implicit conversions when a boolean is expected.

so, the OP problem can be solved either via direct initialization as you suggested, or by triggering an (explicit or contextual)boolean conversion, eg

auto converted = bool{ i >> level };
bool converted = !!( i >> level );
bool converted = ( i >> level ) ? true : false;
// ... whatever