module internal.arrays;

extern(C):

// per-element array init routines

void _d_array_init_i1(bool* a, size_t n, bool v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_i8(ubyte* a, size_t n, ubyte v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_i16(ushort* a, size_t n, ushort v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_i32(uint* a, size_t n, uint v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_i64(ulong* a, size_t n, ulong v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_float(float* a, size_t n, float v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_double(double* a, size_t n, double v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

void _d_array_init_pointer(void** a, size_t n, void* v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}

// array comparison routines
int memcmp(void*,void*,size_t);

bool _d_static_array_eq(void* lhs, void* rhs, size_t bytesize)
{
    if (lhs is rhs)
        return true;
    return memcmp(lhs,rhs,bytesize) == 0;
}

bool _d_static_array_neq(void* lhs, void* rhs, size_t bytesize)
{
    if (lhs is rhs)
        return false;
    return memcmp(lhs,rhs,bytesize) != 0;
}

bool _d_dyn_array_eq(void[] lhs, void[] rhs)
{
    if (lhs.length != rhs.length)
        return false;
    else if (lhs is rhs)
        return true;
    return memcmp(lhs.ptr,rhs.ptr,lhs.length) == 0;
}

bool _d_dyn_array_neq(void[] lhs, void[] rhs)
{
    if (lhs.length != rhs.length)
        return true;
    else if (lhs is rhs)
        return false;
    return memcmp(lhs.ptr,rhs.ptr,lhs.length) != 0;
}

// for array cast
size_t _d_array_cast_len(size_t len, size_t elemsz, size_t newelemsz)
{
    if (newelemsz == 1) {
        return len*elemsz;
    }
    else if (len % newelemsz) {
        throw new Exception("Bad array cast");
    }
    return (len*elemsz)/newelemsz;
}