Structure - Typedef accessing problem

This is a discussion on Structure - Typedef accessing problem within the C Programming forums, part of the General Programming Boards category; Hi, Code: typedef enum RelationalOperators {EQ, NE, GT, LT} Rel_Op; Code: typedef union TokenAttribute{ Rel_Op rel_op; } TA; Code: typedef ...

  1. #1
    eat my shorts!
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    Apr 2002
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    Arrow Structure - Typedef accessing problem

    Hi,

    Code:
    typedef enum RelationalOperators  {EQ, NE, GT, LT} Rel_Op;
    Code:
    typedef union TokenAttribute{
    	Rel_Op rel_op;  
      } TA;
    Code:
    typedef struct Token
    {
    	TA attribute;
    } Token;
    Code:
    token temp;
    
    temp.attribute.rel_op[0];          /*error*/
    i am trying to access the EQ, NE, GT, and LT to do certain operations afterwards - but cant seem to get the syntax right...
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  2. #2
    eat my shorts!
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    Arrow Structure - Typedef accessing problem

    <<threads merged>>

    Code:
    typedef enum RelationalOperators  {EQ, NE, GT, LT} Rel_Op;
    
    
    typedef union TokenAttribute{
    	Rel_Op rel_op;  
      } TA;
    
    typedef struct Token
    {
    	TA attribute; /* token attribute */
    } Token;

    Code:
    Token temp;
    temp.attribute.rel_op[0];       /*error*/
    I have been trying ti access the rel_op as i need to compare the content...but cant seem to get the syntax right...
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  3. #3
    Registered User
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    Code:
     if (temp.attribute.rel_op == EQ)
    will test if the enum contains a particular value. The left hand side of the comparison accesses the value in your variable.

  4. #4
    Registered User whiteflags's Avatar
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    rel_op isn't an array, and you're trying to use it like one. Maybe you should just use an array instead of an enum?

    Honestly it's a little hard to give advice, since I can't tell what you're really trying to do.

  5. #5
    and the hat of wrongness Salem's Avatar
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    > typedef union TokenAttribute
    Is there something you're not telling us, because a union with only one member is a struct.
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