BitVector32 Structure

BitVector32 Structure

 

Provides a simple structure that stores Boolean values and small integers in 32 bits of memory.

Namespace:   System.Collections.Specialized
Assembly:  System (in System.dll)

Public Structure BitVector32

NameDescription
System_CAPS_pubmethodBitVector32(BitVector32)

Initializes a new instance of the BitVector32 structure containing the data represented in an existing BitVector32 structure.

System_CAPS_pubmethodBitVector32(Int32)

Initializes a new instance of the BitVector32 structure containing the data represented in an integer.

NameDescription
System_CAPS_pubpropertyData

Gets the value of the BitVector32 as an integer.

System_CAPS_pubpropertyItem(Int32)

Gets or sets the state of the bit flag indicated by the specified mask.

System_CAPS_pubpropertyItem(BitVector32.Section)

Gets or sets the value stored in the specified BitVector32.Section.

NameDescription
System_CAPS_pubmethodSystem_CAPS_staticCreateMask()

Creates the first mask in a series of masks that can be used to retrieve individual bits in a BitVector32 that is set up as bit flags.

System_CAPS_pubmethodSystem_CAPS_staticCreateMask(Int32)

Creates an additional mask following the specified mask in a series of masks that can be used to retrieve individual bits in a BitVector32 that is set up as bit flags.

System_CAPS_pubmethodSystem_CAPS_staticCreateSection(Int16)

Creates the first BitVector32.Section in a series of sections that contain small integers.

System_CAPS_pubmethodSystem_CAPS_staticCreateSection(Int16, BitVector32.Section)

Creates a new BitVector32.Section following the specified BitVector32.Section in a series of sections that contain small integers.

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the BitVector32.(Overrides ValueType.Equals(Object).)

System_CAPS_pubmethodGetHashCode()

Serves as a hash function for the BitVector32.(Overrides ValueType.GetHashCode().)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current BitVector32.(Overrides ValueType.ToString().)

System_CAPS_pubmethodSystem_CAPS_staticToString(BitVector32)

Returns a string that represents the specified BitVector32.

BitVector32 is more efficient than BitArray for Boolean values and small integers that are used internally. A BitArray can grow indefinitely as needed, but it has the memory and performance overhead that a class instance requires. In contrast, a BitVector32 uses only 32 bits.

A BitVector32 structure can be set up to contain either sections for small integers or bit flags for Booleans, but not both. A BitVector32.Section is a window into the BitVector32 and is composed of the smallest number of consecutive bits that can contain the maximum value specified in CreateSection. For example, a section with a maximum value of 1 is composed of only one bit, whereas a section with a maximum value of 5 is composed of three bits. You can create a BitVector32.Section with a maximum value of 1 to serve as a Boolean, thereby allowing you to store integers and Booleans in the same BitVector32.

Some members can be used for a BitVector32 that is set up as sections, while other members can be used for one that is set up as bit flags. For example, the BitVector32.Item property is the indexer for a BitVector32 that is set up as sections, and the BitVector32.Item property is the indexer for a BitVector32 that is set up as bit flags. CreateMask creates a series of masks that can be used to access individual bits in a BitVector32 that is set up as bit flags.

Using a mask on a BitVector32 that is set up as sections might cause unexpected results.

The following code example uses a BitVector32 as a collection of bit flags.

Imports System
Imports System.Collections.Specialized

Public Class SamplesBitVector32

   Public Shared Sub Main()

      ' Creates and initializes a BitVector32 with all bit flags set to FALSE.
      Dim myBV As New BitVector32(0)

      ' Creates masks to isolate each of the first five bit flags.
      Dim myBit1 As Integer = BitVector32.CreateMask()
      Dim myBit2 As Integer = BitVector32.CreateMask(myBit1)
      Dim myBit3 As Integer = BitVector32.CreateMask(myBit2)
      Dim myBit4 As Integer = BitVector32.CreateMask(myBit3)
      Dim myBit5 As Integer = BitVector32.CreateMask(myBit4)

      ' Sets the alternating bits to TRUE.
      Console.WriteLine("Setting alternating bits to TRUE:")
      Console.WriteLine("   Initial:         {0}", myBV.ToString())
      myBV(myBit1) = True
      Console.WriteLine("   myBit1 = TRUE:   {0}", myBV.ToString())
      myBV(myBit3) = True
      Console.WriteLine("   myBit3 = TRUE:   {0}", myBV.ToString())
      myBV(myBit5) = True
      Console.WriteLine("   myBit5 = TRUE:   {0}", myBV.ToString())
   End Sub 'Main 
End Class 'SamplesBitVector32


' This code produces the following output.
'
' Setting alternating bits to TRUE:
'    Initial:         BitVector32{00000000000000000000000000000000}
'    myBit1 = TRUE:   BitVector32{00000000000000000000000000000001}
'    myBit3 = TRUE:   BitVector32{00000000000000000000000000000101}
'    myBit5 = TRUE:   BitVector32{00000000000000000000000000010101}

The following code example uses a BitVector32 as a collection of sections.

Imports System
Imports System.Collections.Specialized

Public Class SamplesBitVector32

   Public Shared Sub Main()

      ' Creates and initializes a BitVector32.
      Dim myBV As New BitVector32(0)

      ' Creates four sections in the BitVector32 with maximum values 6, 3, 1, and 15.
      ' mySect3, which uses exactly one bit, can also be used as a bit flag.
      Dim mySect1 As BitVector32.Section = BitVector32.CreateSection(6)
      Dim mySect2 As BitVector32.Section = BitVector32.CreateSection(3, mySect1)
      Dim mySect3 As BitVector32.Section = BitVector32.CreateSection(1, mySect2)
      Dim mySect4 As BitVector32.Section = BitVector32.CreateSection(15, mySect3)

      ' Displays the values of the sections.
      Console.WriteLine("Initial values:")
      Console.WriteLine(ControlChars.Tab + "mySect1: {0}", myBV(mySect1))
      Console.WriteLine(ControlChars.Tab + "mySect2: {0}", myBV(mySect2))
      Console.WriteLine(ControlChars.Tab + "mySect3: {0}", myBV(mySect3))
      Console.WriteLine(ControlChars.Tab + "mySect4: {0}", myBV(mySect4))

      ' Sets each section to a new value and displays the value of the BitVector32 at each step.
      Console.WriteLine("Changing the values of each section:")
      Console.WriteLine(ControlChars.Tab + "Initial:    " + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect1) = 5
      Console.WriteLine(ControlChars.Tab + "mySect1 = 5:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect2) = 3
      Console.WriteLine(ControlChars.Tab + "mySect2 = 3:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect3) = 1
      Console.WriteLine(ControlChars.Tab + "mySect3 = 1:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect4) = 9
      Console.WriteLine(ControlChars.Tab + "mySect4 = 9:" + ControlChars.Tab + "{0}", myBV.ToString())

      ' Displays the values of the sections.
      Console.WriteLine("New values:")
      Console.WriteLine(ControlChars.Tab + "mySect1: {0}", myBV(mySect1))
      Console.WriteLine(ControlChars.Tab + "mySect2: {0}", myBV(mySect2))
      Console.WriteLine(ControlChars.Tab + "mySect3: {0}", myBV(mySect3))
      Console.WriteLine(ControlChars.Tab + "mySect4: {0}", myBV(mySect4))

   End Sub 'Main 

End Class 'SamplesBitVector32


' This code produces the following output.
'
' Initial values:
'        mySect1: 0
'        mySect2: 0
'        mySect3: 0
'        mySect4: 0
' Changing the values of each section:
'        Initial:        BitVector32{00000000000000000000000000000000}
'        mySect1 = 5:    BitVector32{00000000000000000000000000000101}
'        mySect2 = 3:    BitVector32{00000000000000000000000000011101}
'        mySect3 = 1:    BitVector32{00000000000000000000000000111101}
'        mySect4 = 9:    BitVector32{00000000000000000000001001111101}
' New values:
'        mySect1: 5
'        mySect2: 3
'        mySect3: 1
'        mySect4: 9

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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