Question

This is my assert function (it wont compile “error C2110: ‘+’ : cannot add two pointers”):

#define CHAR(x) #x

template<typename T>
inline void ASSERT(T x)
{
    if(!x)
    {
        std::string s("ERROR! Assert " + CHAR(x) + " failed. In file " + __FILE__ +
                      " at line " + __LINE__ + ".");
            std::wstring temp(s.length(), L' ');
            std::copy(s.begin(), s.end(), temp.begin());
            getLogger().Write(temp);
        }
    }

Any idea of how to fix it?

Answer 1

String Literals are easily reduced to char pointers, which cannot be added as you try to do with "ERROR! Assert " + CHAR(x) + " failed. In file ".... However, C++ has the handy feature of doing this automatically before compilation! (the preprocessor does this). Even better, it has a handy tool for making wide strings at compile time. So, you want:

#define _T(x) L ## x
#define CHAR(x) #x
#define CHAR2(x) CHAR(x)
#define ASSERT(x) ASSERT2(x, CHAR(x), __FILE__, CHAR2(__LINE__))
#define ASSERT2(x, t, f, l) \
if(!x) \
    getLogger().Write(L"ERROR! Assert " _T(t) L" failed. In file " _T(f) L" at line " _T(l) L".");

http://ideone.com/0ibcj