get max size of Type List in constexpr

max_constexpr.cc

#include <iostream>

struct A {
    uint64_t f1;
};

struct B {
    uint64_t f1;
    uint64_t f2;
};

struct C {
    uint64_t f1;
    uint64_t f2;
    uint64_t f3;
};

template <typename T>
static constexpr T static_max(T a, T b) {
    return a < b ? b : a;
}

template <typename T, typename... Ts>
static constexpr T static_max(T a, Ts... bs) {
    return static_max(a, static_max(bs...));
}

template <class... Types>
constexpr size_t max_size() {
    return static_max(sizeof(Types)...);
};

struct D {
    char all[max_size<A, B, C>() * 3];
};

int main(int argc, char const* argv[]) {
    std::cout << max_size<A, B, C>() << std::endl;
    D d1;
    std::cout << sizeof(d1) << std::endl;
    return 0;
}