42 lines
1.9 KiB
XML
42 lines
1.9 KiB
XML
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<?xml version="1.0"?>
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<clause number="24.4.3" title="The Obsolete attribute">
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<paragraph>The attribute Obsolete is used to mark types and members of types that should no longer be used. <code_example><![CDATA[
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using System;
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[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct |
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AttributeTargets.Enum | AttributeTargets.Interface |
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AttributeTargets.Delegate | AttributeTargets.Method |
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AttributeTargets.Constructor | AttributeTargets.Property |
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AttributeTargets.Field | AttributeTargets.Event)]
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public class ObsoleteAttribute: Attribute
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{
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public ObsoleteAttribute() {...}
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public ObsoleteAttribute(string message) {...}
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public ObsoleteAttribute(string message, bool error) {...}
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public string Message { get {...} }
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public bool IsError{ get {...} }
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}
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]]></code_example></paragraph>
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<paragraph>If a program uses a type or member that is decorated with the Obsolete attribute, then the compiler shall issue a warning or error in order to alert the developer, so the offending code can be fixed. Specifically, the compiler shall issue a warning if no error parameter is provided, or if the error parameter is provided and has the value false. The compiler shall issue a compile-time error if the error parameter is specified and has the value true. </paragraph>
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<paragraph>
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<example>[Example: In the example <code_example><![CDATA[
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[Obsolete("This class is obsolete; use class B instead")]
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class A
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{
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public void F() {}
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}
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class B
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{
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public void F() {}
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}
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class Test
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{
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static void Main() {
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A a = new A(); // warning
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a.F();
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}
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}
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]]></code_example>the class A is decorated with the Obsolete attribute. Each use of A in Main results in a warning that includes the specified message, "This class is obsolete; use class B instead." end example]</example>
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<table_line/>
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</paragraph>
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</clause>
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