| [08ed947] | 1 | // see also C++ investigation in ~/plg2/cfa2/mycode/string/raii/ctor-calls.cpp | 
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|  | 2 |  | 
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|  | 3 | #include <string.hfa> | 
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|  | 4 | #include <string_res.hfa> | 
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|  | 5 |  | 
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|  | 6 | /* | 
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|  | 7 | call_substrOfPart: | 
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|  | 8 | In all cases, of both HL and LL, there is a temporary object. | 
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|  | 9 | It represents narrowing the range, from full-string, to [1..3]. | 
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|  | 10 | The only matter to control is whether that temporary shares edits with the string from which it was created. | 
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|  | 11 | In HL, two knobs control it, and the | 
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|  | 12 | */ | 
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|  | 13 |  | 
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|  | 14 | void calltest_HL() { | 
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|  | 15 |  | 
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|  | 16 | #define HELPER_BODY(param) \ | 
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|  | 17 | sout | "early in helper with " | param; \ | 
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|  | 18 | param[0] = '+'; \ | 
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|  | 19 | sout | "late in helper with " | param; | 
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|  | 20 |  | 
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|  | 21 | void helper1( string   q ) { HELPER_BODY(q) } | 
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|  | 22 | void helper2( string & q ) { HELPER_BODY(q) } | 
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|  | 23 | #undef HELPER_BODY | 
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|  | 24 |  | 
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|  | 25 | string fred; | 
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|  | 26 |  | 
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|  | 27 |  | 
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|  | 28 | sout | "==="; | 
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|  | 29 | sout | "HL: substring of part"; | 
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|  | 30 |  | 
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|  | 31 | sout | "---"; | 
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|  | 32 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 33 | fred = "abcd"; | 
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|  | 34 | sout | "before helper with " | fred; | 
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|  | 35 | helper1( fred(1,3) ); | 
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|  | 36 | sout | "after helper with " | fred; | 
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|  | 37 |  | 
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|  | 38 | sout | "---"; | 
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|  | 39 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 40 | fred = "abcd"; | 
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|  | 41 | sout | "before helper with " | fred; | 
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|  | 42 | helper2( fred(1,3) ); | 
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|  | 43 | sout | "after helper with " | fred; | 
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|  | 44 |  | 
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|  | 45 | sout | "---"; | 
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|  | 46 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 47 | fred = "abcd"; | 
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|  | 48 | sout | "before helper with " | fred; | 
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|  | 49 | helper2( (string){ fred(1,3) } ); | 
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|  | 50 | sout | "after helper with " | fred; | 
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|  | 51 |  | 
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|  | 52 |  | 
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|  | 53 | sout | "==="; | 
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|  | 54 | sout | "HL: substring of whole"; | 
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|  | 55 |  | 
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|  | 56 | sout | "---"; | 
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|  | 57 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 58 | fred = "abcd"; | 
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|  | 59 | sout | "before helper with " | fred; | 
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|  | 60 | helper1( fred(0,4) ); | 
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|  | 61 | sout | "after helper with " | fred; | 
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|  | 62 |  | 
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|  | 63 | sout | "---"; | 
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|  | 64 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 65 | fred = "abcd"; | 
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|  | 66 | sout | "before helper with " | fred; | 
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|  | 67 | helper2( fred(0,4) ); | 
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|  | 68 | sout | "after helper with " | fred; | 
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|  | 69 |  | 
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|  | 70 | sout | "---"; | 
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|  | 71 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 72 | fred = "abcd"; | 
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|  | 73 | sout | "before helper with " | fred; | 
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|  | 74 | helper2( (string){ fred(0,4) } ); | 
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|  | 75 | sout | "after helper with " | fred; | 
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|  | 76 |  | 
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|  | 77 |  | 
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|  | 78 |  | 
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|  | 79 | sout | "==="; | 
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|  | 80 | sout | "HL: whole original string"; | 
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|  | 81 |  | 
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|  | 82 | sout | "---"; | 
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|  | 83 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 84 | fred = "abcd"; | 
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|  | 85 | sout | "before helper with " | fred; | 
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|  | 86 | helper1( fred ); | 
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|  | 87 | sout | "after helper with " | fred; | 
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|  | 88 |  | 
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|  | 89 | sout | "---"; | 
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|  | 90 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 91 | fred = "abcd"; | 
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|  | 92 | sout | "before helper with " | fred; | 
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|  | 93 | helper2( fred ); | 
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|  | 94 | sout | "after helper with " | fred; | 
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|  | 95 |  | 
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|  | 96 | sout | "---"; | 
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|  | 97 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 98 | fred = "abcd"; | 
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|  | 99 | sout | "before helper with " | fred; | 
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|  | 100 | helper2( (string){ fred } ); | 
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|  | 101 | sout | "after helper with " | fred; | 
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|  | 102 | } | 
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|  | 103 |  | 
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|  | 104 | void calltest_LL() { | 
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|  | 105 |  | 
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|  | 106 | #define HELPER_BODY(param) \ | 
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|  | 107 | sout | "early in helper with " | param; \ | 
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|  | 108 | assignAt(param, 0, '+'); \ | 
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|  | 109 | sout | "late in helper with " | param; | 
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|  | 110 |  | 
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|  | 111 | void helper1( string_res & q ) { HELPER_BODY(q) } // arg should always be a temporary constructed with COPY_VALUE | 
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|  | 112 | void helper2( string_res & q ) { HELPER_BODY(q) } // arg can refer to whatever you want | 
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|  | 113 | #undef HELPER_BODY | 
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|  | 114 |  | 
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|  | 115 | /* | 
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|  | 116 | In LL, both functions are translated to the same thing. | 
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|  | 117 | "The only allowed call of #1" becomes respecting the restriction of the comment at helper1. | 
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|  | 118 | A sys call of #2 is different from the only allowed call of #1. | 
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|  | 119 | A trans call of #2 is the same as the only allowed call of #1. | 
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|  | 120 | */ | 
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|  | 121 |  | 
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|  | 122 | string_res fred; | 
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|  | 123 |  | 
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|  | 124 | sout | "==="; | 
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|  | 125 | sout | "LL: substring of part"; | 
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|  | 126 |  | 
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|  | 127 | sout | "---"; | 
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|  | 128 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 129 | fred = "abcd"; | 
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|  | 130 | sout | "before helper with " | fred; | 
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|  | 131 | helper1( (string_res){ fred, COPY_VALUE, 1, 3 } ); | 
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|  | 132 | sout | "after helper with " | fred; | 
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|  | 133 |  | 
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|  | 134 | sout | "---"; | 
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|  | 135 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 136 | fred = "abcd"; | 
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|  | 137 | sout | "before helper with " | fred; | 
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|  | 138 | helper2( (string_res){ fred, SHARE_EDITS, 1, 3 } ); | 
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|  | 139 | sout | "after helper with " | fred; | 
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|  | 140 |  | 
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|  | 141 | sout | "---"; | 
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|  | 142 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 143 | fred = "abcd"; | 
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|  | 144 | sout | "before helper with " | fred; | 
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|  | 145 | helper2( (string_res){ fred, COPY_VALUE, 1, 3 } ); | 
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|  | 146 | sout | "after helper with " | fred; | 
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|  | 147 |  | 
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|  | 148 |  | 
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|  | 149 | sout | "==="; | 
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|  | 150 | sout | "LL: substring of whole"; | 
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|  | 151 |  | 
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|  | 152 | sout | "---"; | 
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|  | 153 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 154 | fred = "abcd"; | 
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|  | 155 | sout | "before helper with " | fred; | 
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|  | 156 | helper1( (string_res){ fred, COPY_VALUE, 0, 4 } ); | 
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|  | 157 | sout | "after helper with " | fred; | 
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|  | 158 |  | 
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|  | 159 | sout | "---"; | 
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|  | 160 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 161 | fred = "abcd"; | 
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|  | 162 | sout | "before helper with " | fred; | 
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|  | 163 | helper2( (string_res){ fred, SHARE_EDITS, 0, 4 } ); | 
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|  | 164 | sout | "after helper with " | fred; | 
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|  | 165 |  | 
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|  | 166 | sout | "---"; | 
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|  | 167 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 168 | fred = "abcd"; | 
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|  | 169 | sout | "before helper with " | fred; | 
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|  | 170 | helper2( (string_res){ fred, COPY_VALUE, 0, 4 } ); | 
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|  | 171 | sout | "after helper with " | fred; | 
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|  | 172 |  | 
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|  | 173 |  | 
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|  | 174 | sout | "==="; | 
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|  | 175 | sout | "LL: whole original string"; | 
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|  | 176 |  | 
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|  | 177 | sout | "---"; | 
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|  | 178 | // Calling a by-val function, the only way it supports, in which it gets a private logical copy. | 
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|  | 179 | fred = "abcd"; | 
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|  | 180 | sout | "before helper with " | fred; | 
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|  | 181 | helper1( (string_res){ fred, COPY_VALUE } ); | 
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|  | 182 | sout | "after helper with " | fred; | 
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|  | 183 |  | 
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|  | 184 | sout | "---"; | 
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|  | 185 | // Calling a by-ref function, sys-style, in which we want to gets its changes as side effects. | 
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|  | 186 | fred = "abcd"; | 
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|  | 187 | sout | "before helper with " | fred; | 
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|  | 188 | helper2( fred ); | 
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|  | 189 | sout | "after helper with " | fred; | 
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|  | 190 |  | 
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|  | 191 | sout | "---"; | 
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|  | 192 | // Calling a by-ref function, trans-style, in which we give it a logical copy, to prevent it from pulluting our gold one. | 
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|  | 193 | fred = "abcd"; | 
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|  | 194 | sout | "before helper with " | fred; | 
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|  | 195 | helper2( (string_res){ fred, COPY_VALUE } ); | 
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|  | 196 | sout | "after helper with " | fred; | 
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|  | 197 | } | 
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|  | 198 |  | 
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|  | 199 |  | 
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|  | 200 |  | 
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|  | 201 | int main() { | 
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|  | 202 |  | 
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|  | 203 | calltest_HL(); | 
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|  | 204 | calltest_LL(); | 
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|  | 205 |  | 
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|  | 206 | } | 
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