如何在C ++模板代码中修复'预期的'primary-expression'错误？

Question

Here's yet another VC9 vs. GCC 4.2 compile error problem. The following code compiles fine with VC9 (Microsoft Visual C++ 2008 SP1) but not with GCC 4.2 on Mac:

struct C
{
    template< typename T >
    static bool big() { return sizeof( T ) > 8; }
};

template< typename X >
struct UseBig
{
    static bool test()
    {
        return X::big< char >(); // ERROR: expected primary-expression
    }                            // before 'char'
};

int main()
{
    C::big< char >();
    UseBig< C >::test();
    return 0;
}

Any ideas how I can fix this?

Answer 1

That should be

return X::template big< char >();

Dependent names from templates are taken to not be types unless you specify that they are via typename and assumed to not be templates unless specified via template .