Question

Quick question (Theory really). I have a variable that its type alternates depending on a value, for example:

8, 16, 24, 32

And I define this by doing, for example:

uint8_t = 10; // example

But, at the minute I’m switching the “number” and repeating the code but declaring the integer value differently. Which, as you can tell, is a lot of wasteful code and I want to code more effectively.

I’m wondering if It’s possible to have template that assigns the variable depending on the value? (If that makes sense)..

if value == 8
  uint8_t = foo;
elseif value == 16
  uint32_t
...

Any ideas or suggestions? Thank you 🙂

Answer 1

Like so:

template <unsigned int N> struct IntN;

template <> struct IntN< 8> { typedef  uint8_t type; };
template <> struct IntN<16> { typedef uint16_t type; };
template <> struct IntN<32> { typedef uint32_t type; };
template <> struct IntN<64> { typedef uint64_t type; };

IntN<8>::type x = 5;

The template argument has to be a constant expression.