adaptTuple

static ref int func1(ref int a, float b, byte c)
{
    return a;
}

alias adpt1 = adaptTuple!func1;
auto t = tuple(4, 1.1f, cast(byte)2);
assert(&adpt1(t) == &(t.field[0]));

// NG; adpt1の引数がlvalueじゃない(std.forwardのような転送)
static assert(!is(typeof({adpt1(tuple(4, 1.1f, cast(byte)2));})));

// naryFun & 事前に型指定あり
alias adpt2 = adaptTuple!(naryFun!"a", int, float, byte);
assert(&adpt2(t) == &(t.field[0])); // forward性
assert(adpt2(tuple(4, 1.1f, cast(byte)2)) == t.field[0]);

// NG; stringはfloatへ暗黙変換不可能
static assert(!is(typeof({adpt2(tuple(1, "foo", cast(byte)2));})));

// OK; realはfloatへ暗黙変換可能
static assert(is(typeof({adpt2(tuple(1, 1.1L, cast(byte)2));})));
assert(adpt2(tuple(1, 1.1L, cast(byte)2)) == 1);

const ct = t;
static assert(is(typeof(adpt2(ct)) == const));

immutable it = t;
static assert(is(typeof(adpt2(it)) == immutable));

shared st = t;
static assert(is(typeof(adpt2(st)) == shared));


assert(adaptTuple!(naryFun!"a")(tuple(1, 2, 3)) == 1);
assert(adaptTuple!(naryFun!"a", int)(tuple(1)) == 1);