I'm trying to create a pointer to a vector of floats that I have, so that I can pass it to a generic function that looks something like this:
foo<Type>(Type *const *, size_t)
However, as I'm somewhat new to c++, I'm having difficulties understanding how the syntax in the first parameter should be interpreted, in particular the " *const * ". What exactly would I need to put as an argument?
Any help would be appreciated!
const applies to the thing on its left, unless there is nothing there, then it applies to the thing on its right instead.
So, in Type *const *, the const applies to the 1st *. So this would mean that the parameter is a non-const pointer (the 2nd *) to a const pointer (the 1st *) to a non-const Type instance. Which would be written like this when calling foo() with a vector of floats:
vector<float> vec;
// populate vec as needed...
float* const ptr = vec.data(); // or: ... = &vec[0];
foo<float>(&ptr, vec.size());
However, depending on what foo() actually does, you probably don't need that extra level of indirection and can remove one of the pointers:
foo<Type>(const Type *, size_t);
vector<float> vec;
// populate vec as needed...
foo<float>(vec.data()/* or: &vec[0] */, vec.size());
