61 lines
2.6 KiB
C++
61 lines
2.6 KiB
C++
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// fig15_13.cpp
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// Manipulating tuples.
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#include <fmt/format.h>
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#include <iostream>
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#include <string>
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#include <tuple>
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// type alias for a tuple representing a hardware part's inventory
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using Part = std::tuple<int, std::string, int, double>;
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// return a part's inventory tuple
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Part getInventory(int partNumber) {
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using namespace std::string_literals; // for string object literals
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switch (partNumber) {
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case 1:
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return {1, "Hammer"s, 32, 9.95}; // return a Part tuple
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case 2:
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return {2, "Screwdriver"s, 106, 6.99}; // return a Part tuple
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default:
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return {0, "INVALID PART"s, 0, 0.0}; // return a Part tuple
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}
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}
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int main() {
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// display the hardware part inventory
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for (int i{1}; i <= 2; ++i) {
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// unpack the returned tuple into four variables;
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// variables' types are inferred from the tuple's element values
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auto [partNumber, partName, quantity, price] {getInventory(i)};
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std::cout << fmt::format("{}: {}, {}: {}, {}: {}, {}: {:.2f}\n",
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"Part number", partNumber, "Tool", partName,
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"Quantity", quantity, "Price", price);
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}
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std::cout << "\nAccessing a tuple's elements by index number:\n";
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auto hammer{getInventory(1)};
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std::cout << fmt::format("{}: {}, {}: {}, {}: {}, {}: {:.2f}\n",
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"Part number", std::get<0>(hammer), "Tool", std::get<1>(hammer),
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"Quantity", std::get<2>(hammer), "Price", std::get<3>(hammer));
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std::cout << fmt::format("A Part tuple has {} elements\n",
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std::tuple_size<Part>{}); // get the tuple size
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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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