49 lines
765 B
C++
49 lines
765 B
C++
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#include <cstdio>
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struct Add {
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template<typename T>
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static auto eval(T lhs, T rhs) {
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return lhs + rhs;
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}
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};
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struct Mul {
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template<typename T>
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static auto eval(T lhs, T rhs) {
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return lhs * rhs;
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}
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};
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template<typename T>
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class Value {
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T _value;
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public:
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Value(T value): _value(value) {}
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auto eval() const { return _value; }
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};
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template<typename Op, typename LHS, typename RHS>
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struct BinExpr {
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LHS lhs;
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RHS rhs;
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auto eval() const {
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return Op::eval(lhs.eval(), rhs.eval());
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}
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};
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int main() {
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using SubExpr = BinExpr<Mul, Value<int>, Value<int>>;
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using MyExpr = BinExpr<Add, Value<int>, SubExpr>;
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int volatile v0 = 3, v1 = 5, v2 = 7;
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int result;
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MyExpr expr{{v0}, {{v1}, {v2}}};
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result = expr.eval();
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std::printf("%d\n", result);
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}
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