When linking with C++ code that uses a negative integer as a template parameter, D will fail to link because it outputs e.g. '-1' instead of 'n1' as required by ABI.

Example:

C++:

template <int x> struct S
{
    int member;
};

void func(S<-1> s) {}

D:

struct S(int x)
{
    int member;
}

extern(C++) void func(S!(-1) s);

void main()
{
    func(S!(-1)(0));
}

result:

Undefined symbols for architecture x86_64:
  "__Z4func1SILi-1EE", referenced from:
      __Dmain in testcpp1.o

I don't know what platforms other than OSX this causes a problem on.

I am working on a pull that fixes this, will post soon.