core/utils/Utility.h

#ifndef CORE_UTILITY_H
#define CORE_UTILITY_H

#include "utils/Check.h"

#define CORE_SIZE(t) static_cast<int>(sizeof(t))

namespace Core {
    namespace Internal {
        template<typename T>
        struct BaseRemoveReference {
            using Type = T;
        };

        template<typename T>
        struct BaseRemoveReference<T&> {
            using Type = T;
        };

        template<typename T>
        struct BaseRemoveReference<T&&> {
            using Type = T;
        };

        template<typename A, typename B>
        struct BaseIsSame {
            static constexpr bool value = false;
        };

        template<typename T>
        struct BaseIsSame<T, T> {
            static constexpr bool value = true;
        };

        template<bool C, typename A, typename B>
        struct BaseIf {
            using Type = A;
        };

        template<typename A, typename B>
        struct BaseIf<false, A, B> {
            using Type = B;
        };
    }

    template<typename T>
    using RemoveReference = Internal::BaseRemoveReference<T>::Type;

    template<typename T, typename U>
    constexpr bool IsSame = Internal::BaseIsSame<T, U>::value;

    template<bool C, typename A, typename B>
    using If = Internal::BaseIf<C, A, B>::Type;

    namespace Internal {
        template<int N, typename T1, typename T2, typename T3, typename T4,
                 typename T5>
        using SelectType =
            If<sizeof(T1) == N, T1,
               If<sizeof(T2) == N, T2,
                  If<sizeof(T3) == N, T3, If<sizeof(T4) == N, T4, T5>>>>;

        template<int N>
        using SelectSigned =
            SelectType<N, signed char, signed short, signed int, signed long,
                       signed long long>;

        template<int N>
        using SelectUnsigned =
            SelectType<N, unsigned char, unsigned short, unsigned int,
                       unsigned long, unsigned long long>;
    }

    template<typename T>
    constexpr RemoveReference<T>&& move(T&& t) {
        return static_cast<RemoveReference<T>&&>(t);
    }

    template<typename T>
    constexpr T&& forward(RemoveReference<T>& t) {
        return static_cast<T&&>(t);
    }

    template<typename T>
    constexpr T&& forward(RemoveReference<T>&& t) {
        return static_cast<T&&>(t);
    }

    template<typename T>
    void swap(T& a, T& b) {
        T tmp = Core::move(a);
        a = Core::move(b);
        b = Core::move(tmp);
    }

    template<typename T>
    int popCount(const T& t) {
        static constexpr int map[16] = {0, 1, 1, 2, 1, 2, 2, 3,
                                        1, 2, 2, 3, 2, 3, 3, 4};
        int sum = 0;
        for(int i = 0; i < CORE_SIZE(T) * 8; i += 4) {
            sum += map[(t >> i) & 0xF];
        }
        return sum;
    }

    using ExitHandler = void (*)(int, void*);

    void exitWithHandler(const char* file, int line, int value);
    void setExitHandler(ExitHandler eh, void*);

#define CORE_EXIT(exitValue)                                                   \
    Core::exitWithHandler(__FILE__, __LINE__, exitValue)

    // returns true on error
    check_return bool toString(signed short s, char* buffer, int size);
    // returns true on error
    check_return bool toString(unsigned short s, char* buffer, int size);
    // returns true on error
    check_return bool toString(signed int i, char* buffer, int size);
    // returns true on error
    check_return bool toString(unsigned int i, char* buffer, int size);
    // returns true on error
    check_return bool toString(signed long l, char* buffer, int size);
    // returns true on error
    check_return bool toString(unsigned long l, char* buffer, int size);
    // returns true on error
    check_return bool toString(signed long long ll, char* buffer, int size);
    // returns true on error
    check_return bool toString(unsigned long long ll, char* buffer, int size);
    // returns true on error
    check_return bool toString(float f, char* buffer, int size);
    // returns true on error
    check_return bool toString(double d, char* buffer, int size);
    // returns true on error
    check_return bool toString(long double ld, char* buffer, int size);

    // returns true on error
    check_return bool putChar(int c);

    void memorySet(void* p, int c, int n);
    void memoryCopy(void* dest, const void* src, int n);
}

using i64 = Core::Internal::SelectSigned<8>;
using i32 = Core::Internal::SelectSigned<4>;
using i16 = Core::Internal::SelectSigned<2>;
using i8 = Core::Internal::SelectSigned<1>;
using u64 = Core::Internal::SelectUnsigned<8>;
using u32 = Core::Internal::SelectUnsigned<4>;
using u16 = Core::Internal::SelectUnsigned<2>;
using u8 = Core::Internal::SelectUnsigned<1>;

static_assert(sizeof(i64) == 8, "invalid size");
static_assert(sizeof(i32) == 4, "invalid size");
static_assert(sizeof(i16) == 2, "invalid size");
static_assert(sizeof(i8) == 1, "invalid size");
static_assert(sizeof(u64) == 8, "invalid size");
static_assert(sizeof(u32) == 4, "invalid size");
static_assert(sizeof(u16) == 2, "invalid size");
static_assert(sizeof(u8) == 1, "invalid size");

using size_t = u64;

void* operator new(size_t bytes) noexcept;
void* operator new[](size_t bytes) noexcept;
void operator delete(void* p) noexcept;
void operator delete[](void* p) noexcept;
void operator delete(void* p, size_t bytes) noexcept;
void operator delete[](void* p, size_t bytes) noexcept;
void* operator new(size_t bytes, void* p) noexcept;
// void* operator new[](size_t bytes, void* p) noexcept;

#endif