59 lines
2.4 KiB
C++
59 lines
2.4 KiB
C++
// fig15_16.cpp
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// Binary fold expressions.
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#include <fmt/format.h>
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#include <iostream>
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template <typename... Items>
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auto binaryLeftAdd(Items... items) {
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return (0 + ... + items); // binary left fold
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}
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template <typename... Items>
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auto binaryRightAdd(Items... items) {
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return (items + ... + 0); // binary right fold
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}
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template <typename... Items>
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auto binaryLeftSubtract(Items... items) {
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return (0 - ... - items); // binary left fold
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}
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template <typename... Items>
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auto binaryRightSubtract(Items... items) {
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return (items - ... - 0); // binary right fold
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}
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int main() {
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std::cout << "Binary left and right fold with addition:"
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<< fmt::format("\n{}{}\n{}{}\n{}{}\n{}{}\n\n",
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"binaryLeftAdd(): ", binaryLeftAdd(),
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"binaryLeftAdd(1, 2, 3, 4): ", binaryLeftAdd(1, 2, 3, 4),
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"binaryRightAdd(): ", binaryRightAdd(),
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"binaryRightAdd(1, 2, 3, 4): ", binaryRightAdd(1, 2, 3, 4));
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std::cout << "Binary left and right fold with subtraction:"
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<< fmt::format("\n{}{}\n{}{}\n{}{}\n{}{}\n",
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"binaryLeftSubtract(): ", binaryLeftSubtract(),
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"binaryLeftSubtract(1, 2, 3, 4): ",
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binaryLeftSubtract(1, 2, 3, 4),
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"binaryRightSubtract(): ", binaryRightSubtract(),
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"binaryRightSubtract(1, 2, 3, 4): ",
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binaryRightSubtract(1, 2, 3, 4));
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}
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/**************************************************************************
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* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
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* Pearson Education, Inc. All Rights Reserved. *
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* *
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* DISCLAIMER: The authors and publisher of this book have used their *
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* best efforts in preparing the book. These efforts include the *
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* development, research, and testing of the theories and programs *
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* to determine their effectiveness. The authors and publisher make *
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* no warranty of any kind, expressed or implied, with regard to these *
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* programs or to the documentation contained in these books. The authors *
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* and publisher shall not be liable in any event for incidental or *
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* consequential damages in connection with, or arising out of, the *
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* furnishing, performance, or use of these programs. *
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**************************************************************************/
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