Implement LCM and GCD for C++17. Same code as for Library Fundamentals TS.
llvm-svn: 276751
diff --git a/libcxx/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp b/libcxx/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp
new file mode 100644
index 0000000..2375a34
--- /dev/null
+++ b/libcxx/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp
@@ -0,0 +1,131 @@
+//===----------------------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <numeric>
+
+// template<class _M, class _N>
+// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
+
+#include <numeric>
+#include <cassert>
+#include <cstdlib>
+#include <iostream>
+
+constexpr struct {
+ int x;
+ int y;
+ int expect;
+} Cases[] = {
+ {0, 0, 0},
+ {1, 0, 0},
+ {0, 1, 0},
+ {1, 1, 1},
+ {2, 3, 6},
+ {2, 4, 4},
+ {3, 17, 51},
+ {36, 18, 36}
+};
+
+template <typename Input1, typename Input2, typename Output>
+constexpr bool test0(Input1 in1, Input2 in2, Output out)
+{
+ static_assert((std::is_same<Output, decltype(std::lcm(Input1(0), Input2(0)))>::value), "" );
+ static_assert((std::is_same<Output, decltype(std::lcm(Input2(0), Input1(0)))>::value), "" );
+ return out == std::lcm(in1, in2) ? true : (std::abort(), false);
+}
+
+
+template <typename Input1, typename Input2 = Input1>
+constexpr bool do_test(int dummy = 0)
+{
+ using S1 = typename std::make_signed<Input1>::type;
+ using S2 = typename std::make_signed<Input2>::type;
+ using U1 = typename std::make_unsigned<Input1>::type;
+ using U2 = typename std::make_unsigned<Input2>::type;
+ bool accumulate = true;
+ for (auto TC : Cases) {
+ { // Test with two signed types
+ using Output = std::common_type_t<S1, S2>;
+ accumulate &= test0<S1, S2, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<S1, S2, Output>(-TC.x, TC.y, TC.expect);
+ accumulate &= test0<S1, S2, Output>(TC.x, -TC.y, TC.expect);
+ accumulate &= test0<S1, S2, Output>(-TC.x, -TC.y, TC.expect);
+ accumulate &= test0<S2, S1, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<S2, S1, Output>(-TC.x, TC.y, TC.expect);
+ accumulate &= test0<S2, S1, Output>(TC.x, -TC.y, TC.expect);
+ accumulate &= test0<S2, S1, Output>(-TC.x, -TC.y, TC.expect);
+ }
+ { // test with two unsigned types
+ using Output = std::common_type_t<U1, U2>;
+ accumulate &= test0<U1, U2, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<U2, U1, Output>(TC.x, TC.y, TC.expect);
+ }
+ { // Test with mixed signs
+ using Output = std::common_type_t<S1, U2>;
+ accumulate &= test0<S1, U2, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<U2, S1, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<S1, U2, Output>(-TC.x, TC.y, TC.expect);
+ accumulate &= test0<U2, S1, Output>(TC.x, -TC.y, TC.expect);
+ }
+ { // Test with mixed signs
+ using Output = std::common_type_t<S2, U1>;
+ accumulate &= test0<S2, U1, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<U1, S2, Output>(TC.x, TC.y, TC.expect);
+ accumulate &= test0<S2, U1, Output>(-TC.x, TC.y, TC.expect);
+ accumulate &= test0<U1, S2, Output>(TC.x, -TC.y, TC.expect);
+ }
+ }
+ return accumulate;
+}
+
+int main()
+{
+ auto non_cce = std::rand(); // a value that can't possibly be constexpr
+
+ static_assert(do_test<signed char>(), "");
+ static_assert(do_test<short>(), "");
+ static_assert(do_test<int>(), "");
+ static_assert(do_test<long>(), "");
+ static_assert(do_test<long long>(), "");
+
+ assert(do_test<signed char>(non_cce));
+ assert(do_test<short>(non_cce));
+ assert(do_test<int>(non_cce));
+ assert(do_test<long>(non_cce));
+ assert(do_test<long long>(non_cce));
+
+ static_assert(do_test< int8_t>(), "");
+ static_assert(do_test<int16_t>(), "");
+ static_assert(do_test<int32_t>(), "");
+ static_assert(do_test<int64_t>(), "");
+
+ assert(do_test< int8_t>(non_cce));
+ assert(do_test<int16_t>(non_cce));
+ assert(do_test<int32_t>(non_cce));
+ assert(do_test<int64_t>(non_cce));
+
+ static_assert(do_test<signed char, int>(), "");
+ static_assert(do_test<int, signed char>(), "");
+ static_assert(do_test<short, int>(), "");
+ static_assert(do_test<int, short>(), "");
+ static_assert(do_test<int, long>(), "");
+ static_assert(do_test<long, int>(), "");
+ static_assert(do_test<int, long long>(), "");
+ static_assert(do_test<long long, int>(), "");
+
+ assert((do_test<signed char, int>(non_cce)));
+ assert((do_test<int, signed char>(non_cce)));
+ assert((do_test<short, int>(non_cce)));
+ assert((do_test<int, short>(non_cce)));
+ assert((do_test<int, long>(non_cce)));
+ assert((do_test<long, int>(non_cce)));
+ assert((do_test<int, long long>(non_cce)));
+ assert((do_test<long long, int>(non_cce)));
+}