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─────C/C++ Language─────────────────────────────────────────────────────────
 
  Keyword:   struct
 
  Syntax:    struct [tag] { member-list } [declarators];
             [struct] tag declarators;
 
  Summary:   Defines a structure type and/or a variable of a
             structure type.
             See: ◄Anonymous Structures►
                  ◄Unsized Array in a Structure►
 
  See also:  class, union, enum
 
     A structure type is a user-defined composite type. It is composed
     of "fields" or "members" that can have different types.
 
     In C++, a structure is the same as a class except that its members
     are public by default.
 
     Declaring a Structure
 
     Use the struct keyword with a <member-list> enclosed by braces to
     declare a structure type. The <tag> identifies the type.
 
     For both C and C++, a data item in the <member-list> can be any
     valid data declaration, including another structure, or it can be
     a bit field in the following form:
 
          int-type-specifier [identifier] : constant-expression
 
     The <int-type-specifier> must be an integral type. The
     <constant-expression> specifies the number of bits in the field.
     Unnamed bit fields can be used for alignment. If an unnamed field
     has width 0, the next field is aligned on the current packing
     boundary as defined by /Zp or the pack pragma.
     See: /Zp, pack
 
     A structure type cannot contain itself as a member. It can
     contain a pointer to itself.
 
     Using A Structure
 
     In C, you must use the following syntax to declare a variable
     as a structure:
 
          struct tag declarator;
 
     You have the option of declaring variables when the structure type
     is defined by placing one or more comma-separated variable names
     between the closing brace and the semicolon.
 
     In C++, the struct keyword is unnecessary once the type has been
     defined. This allows you to declare variables with this syntax:
 
          tag declarator;
 
     As with C, you have the option of declaring variables in the
     declaration of the struct. For example:
 
          struct PERSON           // Declare PERSON struct type
          {
             int   age;           // Members of several types
             long  ss;
             float weight;
             char  name[25];
          } family_member;        // Define object of type PERSON
 
          struct PERSON sister;   // C declaration of a structure
                                  //     variable
          PERSON brother;         // C++ declaration of a
                                  //     structure
 
          sister.age  = 13;       // Assign values to members
          brother.age =  7;
 
     Structure variables can be initialized. The initialization for each
     variable must be enclosed in braces. For example:
 
          struct POINT            // Declare POINT structure
          {
              int x;              // Define members x and y
              int y;
          } here = { 20, 40 };    // Variable here has
                                  //     values x = 20, y = 40
          struct POINT there;     // Variable there has POINT type
          struct CELL             // Declare CELL bit field
          {
              unsigned character  : 8;  // 00000000 ????????
              unsigned foreground : 3;  // 00000??? 00000000
              unsigned intensity  : 1;  // 0000?000 00000000
              unsigned background : 3;  // 0???0000 00000000
              unsigned blink      : 1;  // ?0000000 00000000
          } screen[25][80];       // Array of bit fields
                                    -♦-