| 1 | //
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
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| 3 | //
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| 4 | // The contents of this file are covered under the licence agreement in the
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| 5 | // file "LICENCE" distributed with Cforall.
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| 6 | //
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| 7 | // references.c --
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| 8 | //
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| 9 | // Author           : Rob Schluntz
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| 10 | // Created On       : Wed Aug 23 16:11:50 2017
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| 11 | // Last Modified By : Peter A. Buhr
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| 12 | // Last Modified On : Tue Dec 25 14:31:48 2018
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| 13 | // Update Count     : 11
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| 14 | //
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| 15 | 
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| 16 | #include <fstream.hfa>
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| 17 | 
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| 18 | struct Y { int i; };
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| 19 | void ?{}( Y & y ) { sout | "Default constructing a Y"; }
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| 20 | void ?{}( Y & y, Y other ) { sout | "Copy constructing a Y"; }
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| 21 | void ^?{}( Y & y ) { sout | "Destructing a Y"; }
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| 22 | Y ?=?( Y & y, Y other ) { sout | "Assigning a Y"; return y; }
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| 23 | void ?{}( Y & y, int i ) { sout | "Value constructing a Y" | i; y.i = i; }
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| 24 | 
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| 25 | struct X { Y & r; Y y; };
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| 26 | void ?{}( X & x ) {
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| 27 |         // ensure that r is not implicitly constructed
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| 28 | }
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| 29 | void ?{}( X & x, X other ) {
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| 30 |         // ensure that r is not implicitly constructed
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| 31 | }
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| 32 | void ^?{}( X & x ) {
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| 33 |         // ensure that r is not implicitly destructed
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| 34 | }
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| 35 | X ?=?( X & x, X other ) { return x; }
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| 36 | 
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| 37 | // ensure that generated functions do not implicitly operate on references
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| 38 | struct Z { Y & r; Y y; };
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| 39 | 
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| 40 | // test user-defined reference-returning function
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| 41 | int & toref( int * p ) { return *p; }
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| 42 | // test user-defined reference-parameter function
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| 43 | int * toptr( int & r ) { return &r; }
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| 44 | 
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| 45 | void changeRef( int & r ) {
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| 46 |         r++;
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| 47 | }
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| 48 | 
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| 49 | int main() {
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| 50 |         int x = 123456, x2 = 789, *p1 = &x, **p2 = &p1, ***p3 = &p2,
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| 51 |                 &r1 = x,    &&r2 = r1,   &&&r3 = r2;
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| 52 |         ***p3 = 3;                                                                                      // change x
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| 53 |         **p3 = &x;                                                                                      // change p1
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| 54 |         *p3 = &p1;                                                                                      // change p2
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| 55 |         int y = 0, z = 11, & ar[3] = { x, y, z };                       // initialize array of references
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| 56 |                                                                                                                 // &ar[1] = &z;                        // change reference array element
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| 57 |                                                                                                                 // typeof( ar[1] ) p = 3;              // is int, i.e., the type of referenced object
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| 58 |                                                                                                                 // typeof( &ar[1] ) q = &x;            // is int *, i.e., the type of pointer
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| 59 |         // _Static_assert( sizeof( ar[1] ) == sizeof( int ), "Array type should be int." );   // is true, i.e., the size of referenced object
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| 60 |         // _Static_assert( sizeof( &ar[1] ) == sizeof( int *), "Address of array should be int *." ); // is true, i.e., the size of a reference
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| 61 | 
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| 62 |         ((int*&)&r3) = &x;                                                                      // change r1, (&*)**r3
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| 63 |         x = 3;
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| 64 |         // test that basic reference properties are true - r1 should be an alias for x
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| 65 |         sout | x | r1 | &x == &r1;
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| 66 |         r1 = 12;
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| 67 |         sout | x | r1 | &x == &r1;
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| 68 | 
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| 69 |         // test that functions using basic references work
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| 70 |         sout | toref( &x ) | toref( p1 ) | toptr( r1 ) == toptr( x ) | toptr( r1 ) == &x;
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| 71 | 
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| 72 |         changeRef( x );
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| 73 |         changeRef( y );
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| 74 |         changeRef( z );
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| 75 |         sout | x | y | z;
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| 76 |         changeRef( r1 );
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| 77 |         sout | r1 | x;
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| 78 | 
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| 79 |         r3 = 6;                                                                                         // change x, ***r3
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| 80 |         sout | "x = " | x | " ; x2 = " | x2;                            // check that x was changed
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| 81 |         &r3 = &x2;                                                                                      // change r1 to refer to x2, (&*)**r3
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| 82 |         r3 = 999;                                                                                       // modify x2
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| 83 |         sout | "x = " | x | " ; x2 = " | x2;                            // check that x2 was changed
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| 84 |         ((int**&)&&r3) = p2;                                                            // change r2, (&(&*)*)*r3, ensure explicit cast to reference works
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| 85 |         r3 = 12345;                                                                                     // modify x
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| 86 |         sout | "x = " | x | " ; x2 = " | x2;                            // check that x was changed
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| 87 |         &&&r3 = p3;                                                                                     // change r3 to p3, (&(&(&*)*)*)r3
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| 88 |         ((int&)r3) = 22222;                                                                     // modify x, ensure explicit cast to reference works
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| 89 |         sout | "x = " | x | " ; x2 = " | x2;                                    // check that x was changed
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| 90 | 
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| 91 |         // test that reference members are not implicitly constructed/destructed/assigned
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| 92 |         X x1, x2 = x1;
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| 93 |         x1 = x2;
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| 94 | 
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| 95 |         Z z1, z2 = z1;
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| 96 |         Y z1r = 56, z2r = 78;
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| 97 |         &z1.r = &z1r;
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| 98 |         &z2.r = &z2r;
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| 99 | 
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| 100 |         z1 = z2;
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| 101 | 
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| 102 |         // test rvalue-to-reference conversion
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| 103 |         {
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| 104 |                 struct S { double x, y; };
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| 105 |                 void f( int & i, int & j, S & s, int v[] ) {
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| 106 |                         sout | i | j | "{ " | s.[x, y] | " }," | "[" | v[0] | "," | v[1] | "," | v[2] | "]";
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| 107 |                 }
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| 108 |                 void g(int & i) { sout | i; }
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| 109 |                 void h(int &&& i) { sout | i; }
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| 110 | 
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| 111 |                 int &&& r = 3;                                                                  // rvalue to reference
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| 112 |                 int i = r;
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| 113 |                 sout | i | r;                                                                   // both 3
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| 114 | 
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| 115 |                 g( 3 );                                                                                 // rvalue to reference
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| 116 |                 h( (int &&&)3 );                                                                // rvalue to reference
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| 117 | 
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| 118 |                 int a = 5, b = 4;
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| 119 |                 f( 3, a + b, (S){ 1.0, 7.0 }, (int [3]){ 1, 2, 3 } ); // two rvalue to reference
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| 120 |         }
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| 121 | }
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| 122 | 
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| 123 | // Local Variables: //
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| 124 | // tab-width: 4 //
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| 125 | // End: //
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