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Do not mark enums with FlagsAttribute
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Do not mark enums with FlagsAttribute







Breaking Change

Non Breaking

An externally visible enumeration is marked with FlagsAttribute and it has one or more values that are not powers of two or a combination of the other defined values on the enumeration.

An enumeration should have FlagsAttribute present only if each value defined in the enumeration is a power of two, or a combination of defined values.

To fix a violation of this rule, remove FlagsAttribute from the enumeration.

Do not suppress a warning from this rule.

The following example shows an enumeration, Color, that contains the value 3, which is neither a power of two, nor a combination of any of the defined values. The Color enumeration should not be marked with the FlagsAttribute.

using namespace System;

namespace Samples 
    // Violates this rule    
	public enum class Color    
		None   = 0,        
		Red    = 1,        
		Orange = 3,        
		Yellow = 4    

The following example shows an enumeration, Days, that meets the requirements for being marked with the System.FlagsAttribute.

using namespace System;

namespace Samples 
	public enum class Days    
		None        = 0,        
		Monday      = 1,        
		Tuesday     = 2,        
		Wednesday   = 4,        
		Thursday    = 8,        
		Friday      = 16,        
		All         = Monday| Tuesday | Wednesday | Thursday | Friday    

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