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BootOptionIndex is a lightweight, immutable value type in the Unified.Firmware namespace that wraps a ushort index identifying a specific UEFI Boot#### NVRAM variable. Rather than passing raw ushort values through the API — which carry no semantic meaning on their own — BootOptionIndex makes intent explicit and provides a canonical string representation in the Boot#### format used by the firmware (e.g. index 3 becomes "Boot0003"). Because the struct defines implicit conversions both to and from ushort, you can pass a numeric literal anywhere a BootOptionIndex is expected without any explicit cast.

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Namespace

namespace Unified.Firmware;

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Constructor

public BootOptionIndex(ushort index)
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index
ushort
required
The zero-based 16-bit unsigned integer index of the target Boot#### NVRAM variable. Valid range: 0x0000–0xFFFF.
BootOptionIndex idx = new BootOptionIndex(3);
Console.WriteLine(idx); // Boot0003

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Interfaces Implemented

InterfacePurpose
IEquatable<BootOptionIndex>Value equality against another BootOptionIndex.
IEquatable<ushort>Value equality against a raw ushort.
IComparable<BootOptionIndex>Ordering against another BootOptionIndex.
IComparable<ushort>Ordering against a raw ushort.

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Methods

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ToString

public override string ToString()
Returns the Boot#### string representation of the index. The format string is $"Boot{_index:X4}" — the Boot prefix followed by the index value formatted as exactly four uppercase hexadecimal digits with leading zeros. Returns: string — for example, index 3 → "Boot0003", index 255 → "Boot00FF", index 4096 → "Boot1000". 
BootOptionIndex idx = new BootOptionIndex(3);
string name = idx.ToString(); // "Boot0003"

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Equals

public bool Equals(BootOptionIndex other)
public bool Equals(ushort other)
Compares the wrapped ushort value for equality.
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other
BootOptionIndex or ushort
required
The value to compare against.
Returns: bool — true if the underlying index values are equal.

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CompareTo

public int CompareTo(BootOptionIndex other)
public int CompareTo(ushort other)
Compares the wrapped ushort values using standard numeric ordering. Returns: int — negative if this instance is less than other, zero if equal, positive if greater.

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GetHashCode

public override int GetHashCode()
Returns the hash code of the underlying ushort value. Safe to use as a dictionary key.

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Operators

OperatorSignatureDescription
==BootOptionIndex == BootOptionIndextrue when both wrapped indices are equal.
!=BootOptionIndex != BootOptionIndextrue when the wrapped indices differ.
BootOptionIndex a = new BootOptionIndex(2);
BootOptionIndex b = new BootOptionIndex(2);

Console.WriteLine(a == b); // True
Console.WriteLine(a != b); // False

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Implicit Conversions

BootOptionIndex defines three implicit conversions so that you can use it interchangeably with ushort literals or string variables anywhere the API expects it.
ConversionDirectionNotes
ushort → BootOptionIndexWideningLets you pass a ushort literal (e.g. 0x0003) wherever a BootOptionIndex is required, with no explicit cast.
BootOptionIndex → ushortNarrowingExtracts the raw index value.
BootOptionIndex → string—Calls ToString(), producing "Boot####" with four uppercase hex digits.
// ushort → BootOptionIndex: no cast required
FirmwareBootOption option = FirmwareBootService.ReadLoadOption(0x0003);

// BootOptionIndex → ushort
BootOptionIndex idx = new BootOptionIndex(5);
ushort raw = idx;          // 5
Console.WriteLine(raw);   // 5

// BootOptionIndex → string (implicit, via Console.WriteLine overload)
Console.WriteLine(idx);   // Boot0005

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Usage Patterns

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Passing a literal index

Because ushort implicitly converts to BootOptionIndex, you can pass a hex literal directly to any FirmwareBootService method: 
// Reads Boot0003 — the ushort literal 0x0003 is converted automatically
FirmwareBootOption option = FirmwareBootService.ReadLoadOption(0x0003);
Console.WriteLine(option.Description);

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Working with BootOrder

FirmwareBootService.LoadOrder returns a BootOptionIndex[]. Iterate or index into it directly: 
BootOptionIndex[] order = FirmwareBootService.LoadOrder;

foreach (BootOptionIndex idx in order)
{
    FirmwareBootOption entry = FirmwareBootService.ReadLoadOption(idx);
    Console.WriteLine("{0}: {1}", idx, entry.Description);
    // Prints lines like: Boot0000: Windows Boot Manager
}

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Printing the formatted name

The implicit string conversion and ToString() both produce "Boot####" with four uppercase hex digits: 
BootOptionIndex idx = new BootOptionIndex(3);

// All three lines print "Boot0003"
Console.WriteLine(idx);
Console.WriteLine(idx.ToString());
string s = idx; // implicit conversion
Console.WriteLine(s);

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Comparing indices

BootOptionIndex current = FirmwareBootService.CurrentLoadOptionIndex;

if (current == (BootOptionIndex)0x0000)
    Console.WriteLine("Booted from Boot0000");

// Comparing against a raw ushort using IEquatable<ushort>
if (current.Equals((ushort)0x0001))
    Console.WriteLine("Booted from Boot0001");
BootOptionIndex is a readonly struct. All instances are value types and are copied by value. Assigning one to a variable or passing it to a method never aliases the original.

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