Re-sort #include lines using my handy dandy ./utils/sort_includes.py

[oota-llvm.git] / include / llvm / ADT / STLExtras.h

diff --git a/include/llvm/ADT/STLExtras.h b/include/llvm/ADT/STLExtras.h
index 4e56e4d74470eb4b7d1a223f46ce6aca9868cf91..b10a4f11f85710c2335dcb211cd7f3d38ac54c1a 100644 (file)
--- a/include/llvm/ADT/STLExtras.h
+++ b/include/llvm/ADT/STLExtras.h
@@ -18,6 +18,7 @@
 #define LLVM_ADT_STLEXTRAS_H
 
 #include "llvm/Support/Compiler.h"
+#include <cassert>
 #include <cstddef> // for std::size_t
 #include <cstdlib> // for qsort
 #include <functional>
@@ -558,6 +559,35 @@ struct pair_hash {
   }
 };
 
+/// A functor like C++14's std::less<void> in its absence.
+struct less {
+  template <typename A, typename B> bool operator()(A &&a, B &&b) const {
+    return std::forward<A>(a) < std::forward<B>(b);
+  }
+};
+
+/// A functor like C++14's std::equal<void> in its absence.
+struct equal {
+  template <typename A, typename B> bool operator()(A &&a, B &&b) const {
+    return std::forward<A>(a) == std::forward<B>(b);
+  }
+};
+
+/// Binary functor that adapts to any other binary functor after dereferencing
+/// operands.
+template <typename T> struct deref {
+  T func;
+  // Could be further improved to cope with non-derivable functors and
+  // non-binary functors (should be a variadic template member function
+  // operator()).
+  template <typename A, typename B>
+  auto operator()(A &lhs, B &rhs) const -> decltype(func(*lhs, *rhs)) {
+    assert(lhs);
+    assert(rhs);
+    return func(*lhs, *rhs);
+  }
+};
+
 } // End llvm namespace
 
 #endif