C++ static const template member initialization - c++

Question

I'm having some strange issues trying to initialize a static const member variable of a template class. All of my other static variables initialize fine but for some reason it doesn't like this one. I put together some sample code to test and it doesn't have the problem so I really don't know what's going on.
On top of this I'm also having issues defining functions that use typedefs declared inside of the template class with the same issue saying it can't find the type. This problem I have been able to reproduce though in the code below. I know one way to fix it is to define the function inside of the class, but the function is really large and I'm trying to keep it consistent with having all of the huge functions defined outside of the class to make the class definition easier to read. If that's my only option though then I guess I'll have to make an exception...
class tTestType
{
public:
tTestType(int32_t val) : fValue(val) { }
private:
int32_t fValue;
};
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
typedef std::vector<int32_t> tSomeVec;
tSomeVec mTestFunction() const;
static const tTestType kTestStatic;
};
// Should cause the following errors but I can't reproduce them for some reason:
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// error C2988: unrecognizable template declaration/definition
// error C2059: syntax error : 'constant'
template<class T>
const tTestType tTestTemplate<T>::kTestStatic(10);
// Causes the following errors:
// error C2143: syntax error : missing ';' before 'tTestTemplate<T>::mTestFunction'
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// fatal error C1903: unable to recover from previous error(s); stopping compilation
template<class T>
tTestTemplate<T>::tSomeVec tTestTemplate<T>::mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}

Answer 1

Thanks to a coworker I've figured out a solution to both issues.
For the first issue, the static member variable, I've moved the definition to the CPP file and used a template specialization. The reason this doesn't break in the test code I posted is because the basic type (int, float, etc.) handle the problem, but if you use a more complex type, like a class, then it should cause the error. This solution isn't the best thing in the world to do, I know, but it's the only thing that works that is somewhat clean. If someone has a better solution please let me know:
template<>
const tTestType tTestTemplate<uint32_t>::kTestStatic(10);
For the second issue, the function using a type declared inside the class, I went with the solution I described in the initial post and just moved the function definition inside of the template class so now it looks like this:
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
typedef std::vector<int32_t> tSomeVec;
// Declaring the function inside the class to fix the compiler error.
tSomeVec mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}
static const tTestType kTestStatic;
};

Answer 2

I made 2 changes in your code and its compiling fine.
class tTestType
{
public:
tTestType(int32_t val) : fValue(val) { }
private:
int32_t fValue;
};
typedef std::vector<int32_t> tSomeVec;
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
tSomeVec mTestFunction() const;
static const tTestType kTestStatic;
};
// Should cause the following errors but I can't reproduce them for some reason:
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// error C2988: unrecognizable template declaration/definition
// error C2059: syntax error : 'constant'
template<class T>
const tTestType tTestTemplate<T>::kTestStatic(10);
// Causes the following errors:
// error C2143: syntax error : missing ';' before 'tTestTemplate<T>::mTestFunction'
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// fatal error C1903: unable to recover from previous error(s); stopping compilation
template<class T>
tSomeVec tTestTemplate<T>::mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}