UnaryPlus Method (Expression)
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Expression.UnaryPlus Method (Expression)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Creates a UnaryExpression that represents a unary plus operation.

Namespace:  System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

public static UnaryExpression UnaryPlus(
	Expression expression
)

Parameters

expression
Type: System.Linq.Expressions.Expression
An Expression to set the Operand property equal to.

Return Value

Type: System.Linq.Expressions.UnaryExpression
A UnaryExpression that has the NodeType property equal to UnaryPlus and the Operand property set to the specified value.

ExceptionCondition
ArgumentNullException

expression is null.

InvalidOperationException

The unary plus operator is not defined for expression.Type.

The Method property of the resulting UnaryExpression is set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted and IsLiftedToNull properties are both true. Otherwise, they are false.

Implementing Method

The following rules determine the implementing method for the operation:

  • If expression.Type is a user-defined type that defines the unary plus operator, the MethodInfo that represents that operator is the implementing method.

  • Otherwise, if expression.Type is a numeric type, the implementing method is null.

Node Type and Lifted versus Non-Lifted

If the implementing method is not null:

  • If expression.Type is assignable to the argument type of the implementing method, the node is not lifted. The type of the node is the return type of the implementing method.

  • If the following two conditions are satisfied, the node is lifted and the type of the node is the nullable type that corresponds to the return type of the implementing method:

    • expression.Type is a nullable value type and the corresponding non-nullable value type is equal to the argument type of the implementing method.

    • The return type of the implementing method is a non-nullable value type.

If the implementing method is null, the type of the node is expression.Type. If expression.Type is non-nullable, the node is not lifted. Otherwise, the node is lifted.

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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