1 files changed, 125 insertions, 0 deletions
diff --git a/test/std/algorithms/alg.sorting/alg.clamp/clamp.pass.cpp b/test/std/algorithms/alg.sorting/alg.clamp/clamp.pass.cpp
new file mode 100644
index 000000000000..779c41827c92
--- /dev/null
+++ b/test/std/algorithms/alg.sorting/alg.clamp/clamp.pass.cpp
@@ -0,0 +1,125 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+// XFAIL: c++98, c++03, c++11, c++14
+
+// template<class T>
+//   const T&
+//   clamp(const T& v, const T& lo, const T& hi);
+
+#include <algorithm>
+#include <cassert>
+
+struct Tag {
+	Tag() : val(0), tag("Default") {}
+	Tag(int a, const char *b) : val(a), tag(b) {}
+	~Tag() {}
+		
+	int val;
+	const char *tag;
+	};
+	
+bool eq(const Tag& rhs, const Tag& lhs) { return rhs.val == lhs.val && rhs.tag == lhs.tag; }
+// bool operator==(const Tag& rhs, const Tag& lhs) { return rhs.val == lhs.val; }
+bool operator< (const Tag& rhs, const Tag& lhs) { return rhs.val <  lhs.val; }
+
+template <class T>
+void
+test(const T& a, const T& lo, const T& hi, const T& x)
+{
+    assert(&std::clamp(a, lo, hi) == &x);
+}
+
+int main()
+{
+    {
+    int x = 0;
+    int y = 0;
+    int z = 0;
+    test(x, y, z, x);
+    test(y, x, z, y);
+    }
+    {
+    int x = 0;
+    int y = 1;
+    int z = 2;
+    test(x, y, z, y);
+    test(y, x, z, y);
+    }
+    {
+    int x = 1;
+    int y = 0;
+    int z = 1;
+    test(x, y, z, x);
+    test(y, x, z, x);
+    }
+
+    {
+//  If they're all the same, we should get the value back.
+    Tag x{0, "Zero-x"};
+    Tag y{0, "Zero-y"};
+    Tag z{0, "Zero-z"};
+    assert(eq(std::clamp(x, y, z), x));
+    assert(eq(std::clamp(y, x, z), y));
+    }
+
+    {
+//  If it's the same as the lower bound, we get the value back.
+    Tag x{0, "Zero-x"};
+    Tag y{0, "Zero-y"};
+    Tag z{1, "One-z"};
+    assert(eq(std::clamp(x, y, z), x));
+    assert(eq(std::clamp(y, x, z), y));
+    }
+
+    {
+//  If it's the same as the upper bound, we get the value back.
+    Tag x{1, "One-x"};
+    Tag y{0, "Zero-y"};
+    Tag z{1, "One-z"};
+    assert(eq(std::clamp(x, y, z), x));
+    assert(eq(std::clamp(z, y, x), z));
+    }
+
+    {
+//  If the value is between, we should get the value back
+    Tag x{1, "One-x"};
+    Tag y{0, "Zero-y"};
+    Tag z{2, "Two-z"};
+    assert(eq(std::clamp(x, y, z), x));
+    assert(eq(std::clamp(y, x, z), x));
+    }
+
+    {
+//  If the value is less than the 'lo', we should get the lo back.
+    Tag x{0, "Zero-x"};
+    Tag y{1, "One-y"};
+    Tag z{2, "Two-z"};
+    assert(eq(std::clamp(x, y, z), y));
+    assert(eq(std::clamp(y, x, z), y));
+    }
+    {
+//  If the value is greater than 'hi', we should get hi back.
+    Tag x{2, "Two-x"};
+    Tag y{0, "Zero-y"};
+    Tag z{1, "One-z"};
+    assert(eq(std::clamp(x, y, z), z));
+    assert(eq(std::clamp(y, z, x), z));
+    }
+
+    {
+    typedef int T;
+    constexpr T x = 1;
+    constexpr T y = 0;
+    constexpr T z = 1;
+    static_assert(std::clamp(x, y, z) == x, "" );
+    static_assert(std::clamp(y, x, z) == x, "" );
+    }
+}