64ビットデータモデル

64bit_data_model.cpp

// This file is LICENSED WITH https://gist.github.com/KisaragiEffective/a0aba5fd0ed0ab7c5839a5cb3038b9bc
using namespace std;
#include <iostream>
#include <limits>

template <class T>
constexpr int bits(T t) {
    return std::numeric_limits<T>::digits;
}

constexpr bool is_LP64() {
    return bits(static_cast<unsigned int>(1)) == 32
        && bits(static_cast<unsigned long>(1)) == 64
        && sizeof(int*) == 8;
}

constexpr bool is_ILP64() {
    return bits(static_cast<unsigned int>(1)) == 64
        && bits(static_cast<unsigned long>(1)) == 64
        && sizeof(int*) == 8;
}

constexpr bool is_LLP64() {
    return bits(static_cast<unsigned int>(1)) == 32
        && bits(static_cast<unsigned long>(1)) == 32
        && bits(static_cast<unsigned long long>(1)) == 64
        && sizeof(int*) == 8;
}

template <class T>
constexpr long bytes() {
    return sizeof(T);
}

int main() {
    cout << "LP64?: " << is_LP64() << endl;
    cout << "ILP64?: " << is_ILP64() << endl;
    cout << "LLP64?: " << is_LLP64() << endl;
    cout << "sizeof<long>:" << bytes<long>();
}