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Programming-Idioms

# 309 Clone a 2D array
Create the new 2-dimensional array y containing a copy of the elements of the 2-dimensional array x.

x and y must not share memory. Subsequent modifications of y must not affect x.
New implementation

Be concise.

Be useful.

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Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations 
integer, allocatable, dimension(:,:) :: y

y = x
buf := make([]T, m*n)
y = make([][]T, m)
for i := range y {
	y[i] = buf[:n:n]
	buf = buf[n:]
	copy(y[i], x[i])
}
func clone2D[M ~[][]T, T any](in M) (out M) {
	if len(in) == 0 {
		return nil
	}

	m, n := len(in), len(in[0])

	buf := make([]T, m*n)

	out = make(M, m)
	for i := range out {
		out[i] = buf[:n:n]
		buf = buf[n:]
		copy(out[i], in[i])
	}
	return out
}
import static java.lang.reflect.Array.newInstance;
import static java.util.Arrays.copyOf;
Class<?> c = x.getClass().getComponentType();
T y[][] = (T[][]) newInstance(c, x.length);
int i = 0;
for (T t[] : x) y[i++] = copyOf(t, t.length);
import static java.util.Arrays.copyOf;
int i = 0, y[][] = new int[x.length][];
for (int t[] : x) y[i++] = copyOf(t, t.length);
import static java.util.Arrays.copyOf;
int i, m = x.length, n,
    y[][] = new int[m][], t[];
for (i = 0; i < m; ++i) {
    n = (t = x[i]).length;
    y[i] = copyOf(t, n);
}
y := x;
y := copy(x, Low(x), Length(x));
use Storable qw(dclone);
$y = dclone($x);
import copy
y = copy.deepcopy(x)
y = Marshal.load(Marshal.dump(x))
let y = x.clone();

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