C++ templates — compilation time vs execution time

Table of contents

Will be evaluated in execution time:

template <typename T>
T cube(const T &value) {
  return value * value * value;
}

Will be evaluated in compilation time:

template <int toCube>
struct Cube {
  enum { value = toCube * toCube * toCube };
};

  fmt::print("8 cubed = {} (execution time)\n", int(cube(8)));
  fmt::print("5 cubed = {} (compilation time)\n", int(Cube<5>::value));

Possible output

8 cubed = 512 (execution time)
5 cubed = 125 (compilation time)