Contract.OldValue<'T> Method ('T)

 
System_CAPS_noteNote

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Represents values as they were at the start of a method or property.

Namespace:   System.Diagnostics.Contracts
Assembly:  mscorlib (in mscorlib.dll)

static member OldValue<'T> : 
        value:'T -> 'T

Parameters

value
Type: T

The value to represent (field or parameter).

Return Value

Type: T

The value of the parameter or field at the start of a method or property.

Type Parameters

T

The type of value.

This method can be used only in the conditional expression for the Ensures contract.

The following example shows the use of the OldValue<'T> method to ensure that a count has been updated. This code example is part of a larger example provided for the ContractClassAttribute class.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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