55 lines
2.1 KiB
C++
55 lines
2.1 KiB
C++
// fig15_15.cpp
|
|
// Unary fold expressions.
|
|
#include <fmt/format.h>
|
|
#include <iostream>
|
|
|
|
template <typename... Items>
|
|
auto unaryLeftAdd(Items... items) {
|
|
return (... + items); // unary left fold
|
|
}
|
|
|
|
template <typename... Items>
|
|
auto unaryRightAdd(Items... items) {
|
|
return (items + ...); // unary right fold
|
|
}
|
|
|
|
template <typename... Items>
|
|
auto unaryLeftSubtract(Items... items) {
|
|
return (... - items); // unary left fold
|
|
}
|
|
|
|
template <typename... Items>
|
|
auto unaryRightSubtract(Items... items) {
|
|
return (items - ...); // unary right fold
|
|
}
|
|
|
|
int main() {
|
|
std::cout << "Unary left and right fold with addition:"
|
|
<< fmt::format("\n{}{}\n{}{}\n\n",
|
|
"unaryLeftAdd(1, 2, 3, 4): ", unaryLeftAdd(1, 2, 3, 4),
|
|
"unaryRightAdd(1, 2, 3, 4): ", unaryRightAdd(1, 2, 3, 4));
|
|
|
|
std::cout << "Unary left and right fold with subtraction:"
|
|
<< fmt::format("\n{}{}\n{}{}\n",
|
|
"unaryLeftSubtract(1, 2, 3, 4): ",
|
|
unaryLeftSubtract(1, 2, 3, 4),
|
|
"unaryRightSubtract(1, 2, 3, 4): ",
|
|
unaryRightSubtract(1, 2, 3, 4));
|
|
}
|
|
|
|
|
|
/**************************************************************************
|
|
* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
|
|
* Pearson Education, Inc. All Rights Reserved. *
|
|
* *
|
|
* DISCLAIMER: The authors and publisher of this book have used their *
|
|
* best efforts in preparing the book. These efforts include the *
|
|
* development, research, and testing of the theories and programs *
|
|
* to determine their effectiveness. The authors and publisher make *
|
|
* no warranty of any kind, expressed or implied, with regard to these *
|
|
* programs or to the documentation contained in these books. The authors *
|
|
* and publisher shall not be liable in any event for incidental or *
|
|
* consequential damages in connection with, or arising out of, the *
|
|
* furnishing, performance, or use of these programs. *
|
|
**************************************************************************/
|