Created
July 31, 2018 05:25
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Example of piping functions
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| #include <cassert> | |
| namespace lab { | |
| class result { | |
| bool success = false; | |
| int value = 0; | |
| public: | |
| result() = default; | |
| result(int x) : success(true), value(x) {} | |
| operator bool() const { return success; } | |
| int operator*() const { return value; } | |
| }; | |
| template<typename A, typename B> | |
| auto operator|(A a, B b) { | |
| if (a) return b(*a); | |
| return a; | |
| } | |
| } // namespace lab | |
| auto a(int x) { return lab::result(x+1); } | |
| auto b(int x) { return lab::result(x*x); } | |
| auto c(int x) { | |
| // return result(); // make it fail | |
| return lab::result(x-1); | |
| } | |
| auto d(int x) { | |
| // assert(false); // check that d don't run | |
| return lab::result(x+10); | |
| } | |
| int main(void) | |
| { | |
| const auto r = a(1) | b | c | d; | |
| assert(r); | |
| assert(*r == 13); | |
| return 0; | |
| } |
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