Question

Why doesn’t the following produce a compiler error?

template<typename T>
const T testFunc()
{
    return T();
}

float* ptr = testFunc<float*>(); // ptr is not const - should be a compiler error!

In this example, testFunc() should be returning a constant float*, so shouldn’t there be a compiler error when I try to assign it to a non-const float* ?

Answer 1

You are wrong on your expectations, the returned pointer will be const, not the object pointed. The specialization is equivalent to:

float * const testFunc<float*>();

Rather than:

float const * testFunc<float*>();

In your example, the code at the call side is copying from a const pointer to a non-const pointer, which is fine.