PKHeX/PKHeX.Core/Items/ItemStorage1.cs

using System;

namespace PKHeX.Core;

public sealed class ItemStorage1 : IItemStorage
{
    public static readonly ItemStorage1 Instance = new();
    private ItemStorage1() { }

    private static ReadOnlySpan<ushort> Pouch_Items_RBY =>
    [
        000,001,002,003,004,005,006,            010,011,012,013,014,015,
        016,017,018,019,020,                                029,030,031,
        032,033,034,035,036,037,038,039,040,041,042,043,    045,046,047,
        048,049,    051,052,053,054,055,056,057,058,    060,061,062,063,
        064,065,066,067,068,069,070,071,072,073,074,075,076,077,078,079,
        080,081,082,083,

        // ...

        196,197,198,199,200,201,202,203,204,205,206,207,
        208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
        224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
        240,241,242,243,244,245,246,247,248,249,250,
    ];

    public bool IsLegal(InventoryType type, int itemIndex, int itemCount) => true;

    public ReadOnlySpan<ushort> GetItems(InventoryType type) => Pouch_Items_RBY;
}