Hi everybody!
After severals hours of struggling with compilation my c++ code in Esenthel Engine I want to share with some of my remarks.
First, I found the EE a very original and innovatory idea. It is quite different from what you can find in today's game development world. Someone may say that this is a disadventage, but I think that a progress is powered by the innovations. So, I regard EE as a very positive occurence, but I found that some work have to be done on it, because there are some lacks and even bugs in it. Besides the lack of inline methods (see the thread I previously started:
link) there are two of them that I have found recently (both releated to c++ templates compilation) :
1. C++ code-reorganization made by EE transforms static variables declared in template class wrong. I mean the variables dependent on template argument. E. g. lets take a classic example of simple singleton pattern:
Code:
template <typename TT> class Singleton
{
static TT* sSingleton = 0;
public:
Singleton()
{
if (sSingleton)
{
throw std::exception("Attempt to recreate a singleton!");
}
sSingleton = static_cast<TT*>(this);
}
virtual ~Singleton() { sSingleton = 0; }
static TT* getSingleton() { return sSingleton; }
};
class SomeSingleton : public Singleton<SomeSingleton>
{
....
};
After code-reoragnization the static definition of
sSingleton should go to header file with templates, but it goes to .cpp file and is even not marked as template:
Code:
// Singleton.cpp:
TT* Singleton<TT>::sSingleton = 0;
Of course such a code couses compilation error. It's evident bug, I think.
2. Free template functions placed in namespace do not compile when Android target is selected. The reason of it is that after the code-reorganization the function names are prepended by namespace name although the functions are yet enclosed in namespace scope. There is an example:
Code:
namespace SomeNamespace
{
template <typename TT> TT fun(TT arg)
{
return sin(cos(arg));
}
}
After code-reorganization the function definition goes to a heder file with templates, but in this way:
Code:
// Some.template.h:
namespace SomeNamespace
{
template <typename TT> TT SomeNamespace::fun(TT arg)
{
return sin(cos(arg));
}
}
As I know, such a redundant explicit qualification is forbidden in modern c++ (e.g. c++11). However it compiles when Windows target is selected. But it does not compile for Android target (compiler used for Android target is probably more restrictive in sticking to the c++ standard). The same applies to member functions of template class, and maybe also to template member functions (but I didn't check the last case).
So the second bug is: redundant namespace qualification of templates.
As I tried to resolve this problem I found that probably there is no walkaroud of this bug unless you give up using namespaces.
So these are the problems I met when compiling some of my c++ code. When I find something more I will make a new post. Now I think it will be nice these bugs will be fixed in the next releases of EE, so the more advanced code using templates will compile.
/
Problems with some c++ templates compilation
